California smog analysis, ask a smog tech

[noahwins]

Hi everyone, I'm a STAR certified smog tech in California. If you're having trouble passing emissions, have questions about emissions equipment or anything else related to smog, let me know!

[camoit]

I have one. Will California ever do the rolling end of smog year. They started to do it way back in the 90's then stopped. I was hopping my Camo truck would be exempt but they stopped the 25 year roll back just before my 25th year. :(

[noahwins]

I doubt it. Gov. Arnold stopped the rolling exemption during the 2003 budget crisis to keep one revenue stream open and it's been stuck at 1976 ever since. California wants to get old cars off the road to meet their air pollution reduction goals (high priority in eco-conscious California). That's what the new STAR program is designed to do: weed out old vehicles. People bring STAR renewals to me all the time and ask me what the program is. If I was blunt I'd say "If California can't get your car off the road this year, they'll try again in two years and every two years after that."

If older vehicles are exempt, the state has no way to force them to be retired. The state's not going to give up that leverage willingly.

[wrencher903]

ive got a 92 mighty max 4cyl 2wd. i have no vaccuum to egr. when i probe the first wire
on the harness plug to the solenoid it has power, when i ck the second wire it also has power but the
vacuum begins to work. once i remove the probe (break ground with test light) i loose
vacuum any ideas.

[camoit]

ive got a 92 mighty max 4cyl 2wd. i have no vaccuum to egr. when i probe the first wire
on the harness plug to the solenoid it has power, when i ck the second wire it also has power but the
vacuum begins to work. once i remove the probe (break ground with test light) i loose
vacuum any ideas.

The EGR will only have vacuum to it under a cruse condition. Unless you feel it's not working for some reason then it should be correct. That would show up in a test on the dyno.

[wrencher903]

do you think grounding the wire so the egr will operate would be ok, at least long enough to get it smogged

[camoit]

Have you taken the egr valve off and cleaned it out?

[Lon Moer]

- can I pass the visual with a CAI set-up if all the emmissions equipment is still in place and working?
- can I pass the visual with an exhaust header set-up if all the emmissions equipment is still in place and working?

[noahwins]

- can I pass the visual with a CAI set-up if all the emmissions equipment is still in place and working?
- can I pass the visual with an exhaust header set-up if all the emmissions equipment is still in place and working?

Not without CARB EO (Executive Order) labels on the equipment or the radiator support for the CAI and headers to be legal. Some inspectors might be lenient and ignore the CAI if nothing after the sensor or PCV breather inlet is modified but by the book, that's a fail. If the headers are long tube and don't look "stock," the inspector will fail it too. The reasoning is the headers and intake alter the power band and hence emissions.

Post a picture of the setup and I'll give you an idea of what an inspector will think.

[noahwins]

ive got a 92 mighty max 4cyl 2wd. i have no vaccuum to egr. when i probe the first wire
on the harness plug to the solenoid it has power, when i ck the second wire it also has power but the
vacuum begins to work. once i remove the probe (break ground with test light) i loose
vacuum any ideas.

There should be no vacuum at idle. The functional test to see if the EGR is working properly is to disconnect the vac line with the engine warmed up and idling and apply vacuum with a handheld pump until the engine stumbles. It should start stumbling be around 5 psi. EGR helps cut down on NOx, it reburns unburned exhaust. Sometimes they get clogged with soot, if it's fouled up, take it off and clean it out with carb cleaner and a wire brush.

[noahwins]

Links to CARB Executive Order database for aftermarket parts and catalytic converters:

http://www.arb.ca.gov/msprog/aftermkt/devices/amquery.php

http://www.arb.ca.gov/msprog/aftermktcat/exemptcatpreobdii.pdf

If you get a new cat installed, make sure the CARB EO# (D-XXX-XX) is on the bottom of the cat, so the inspector can see it. It sucks when someone brings in a car with a legal aftermarket cat, but the shop installed it upside down so I can't get the serial number and I have to fail it! Make sure the D-XXX-XX number is on the BOTTOM and visible.

[mikewarme]

Hey guys, whats the deal with the first converter on a the 2.0 engine? I have an 84 and noticed the 2nd one can be purchased as a direct bolt on California legal but the 1st one is obsolete and no longer available. Can they be gutted out? Mine only has 33,000 original miles so I'm sure there good for awhile but I am investigating poor mileage and a miss when shes cold. Also surges here and there when cold. I am building up a parts cache to keep her serviceable for time to come LOL.

Mike

[mikewarme]

One more thing my egr has a secondary diaphragm on it . See airtex 4f1468. You think I could get away with a standard egr without the diaphragm or would a tech look at my vaccum diagram and notice it missing ?

[mikewarme]

Well ?

[camoit]

Hey guys, whats the deal with the first converter on a the 2.0 engine? I have an 84 and noticed the 2nd one can be purchased as a direct bolt on California legal but the 1st one is obsolete and no longer available. Can they be gutted out? Mine only has 33,000 original miles so I'm sure there good for awhile but I am investigating poor mileage and a miss when shes cold. Also surges here and there when cold. I am building up a parts cache to keep her serviceable for time to come LOL.

Mike

The first one is a cat pre-heater. If you replace the cat with a new one you don't need the heater. The newer cats can clean up emissions better and will work at the lower temperature then the old ones needed to run. There also more efficient then the old one. And for the cost of the new replacement it is less money then trying to replace the heater and the cat. If you could find one. At least that's what I have herd.

And as for the EGR you can probably get away with using the single. I don't think the tech will notice. The duel diagram type is to give a finer control of the gas flow. Not just on or off like the single. Unless the Tech is supper hip to what these trucks have I can't see him asking any questions. All he is going to do is look to see if it's hooked up. I don't think they even put a vacuum pump on them any more to test them. But I do know if you reset the computer in new cars you must first drive them about 20 miles before you can test them, or they will send you out the door.

[mikewarme]

The first one is a cat pre-heater. If you replace the cat with a new one you don't need the heater. The newer cats can clean up emissions better and will work at the lower temperature then the old ones needed to run. There also more efficient then the old one. And for the cost of the new replacement it is less money then trying to replace the heater and the cat. If you could find one. At least that's what I have herd.

And as for the EGR you can probably get away with using the single. I don't think the tech will notice. The duel diagram type is to give a finer control of the gas flow. Not just on or off like the single. Unless the Tech is supper hip to what these trucks have I can't see him asking any questions. All he is going to do is look to see if it's hooked up. I don't think they even put a vacuum pump on them any more to test them. But I do know if you reset the computer in new cars you must first drive them about 20 miles before you can test them, or they will send you out the door.

*****, Thanks for the clarification. Now the trick is to find a manifold that does not have the mounting for a pre heater.

Thanks!

[noahwins]

Unless the Tech is supper hip to what these trucks have I can't see him asking any questions. All he is going to do is look to see if it's hooked up. I don't think they even put a vacuum pump on them any more to test them. But I do know if you reset the computer in new cars you must first drive them about 20 miles before you can test them, or they will send you out the door.

I don't test EGR functionality unless it's pre-OBD2 (1995 or older) and a Two Speed Idle test. So either AWD or if you live in a Basic Area where they don't do the dyno test.

If someone fails you for a non-stock EGR, I'd go to the state referee and appeal it. Because we're not looking for CARB EO#s on any emissions equipment except cats. So long as the EGR is there and it works, you should have no problems.

You can gut the cat because obviously it's not going to throw an OBD code. So long as the second cat is nice and hot and cleans the exhaust enough to pass the tailpipe, the inspector will have no way of knowing the first cat is gutted.

[camoit]

As long as the EGR makes it idle like crap when they pull it open it's good to go. The cat heater is probably a ball of molten crap by now anyway. Just drive a stake through it and put on a new cat. Technology has changed so much from 84 to what they put in there now it can clean up things so much better then before. I wish Cali would just do a tail pipe test and call it good. If they would then we could do so much more with the truck. But the rice racers ruined that years ago. Thats when they came up with the law that say you can't change emission related items. One of them ran into a senator or a congressman's kids car and that pissed them off. Just like the diesels that smoke because they wanted to hot rod there Cummins. One of them saw the smoke and said OMG,,, I need to fix that. , I'm an elected official sworn into office and will always say, SCREW THE GOVERNMENT

[mikewarme]

Screw our government, and the people who voted for the worst president ever. The liberals want to make us scrap our trucks to get carbon credits. Lol you think even with only 34,000 now on the odometer it is toast? I was looking in the 2nd gen parts book and noticed they did not use a heater on the 2nd gen so i am thinking a 2nd gen manifold would bolt up to my 2.0 ? Than it would have a clean look. Trying to maintain this truck in it's nice condition although removing the heater would not be original. Since the parts are obsolete I would rather get rid of the heater and update it now.

[noahwins]

All of your diesel trucks are exempt from smog checks forever, what are you complaining about?

[pennyman1]

I always thought the first cat was a precat - meant to clean up the exhaust until the main cat lit off at operating temp. That always was a cali thing from 1980 on - just slide a pipe through it and problem solved, but collect the stuff from the cat and cash it in - it contains platinum, rhobidium and other precious metals worth a lot of money these days. The old pellet convertors of the 70's are worth a fortune as they are loaded with the metal - the newer honeycomb ones don't have anywhere nearas much metal in them to work.

[noahwins]

Hey guys, check this out, plug in your numbers and it calculates trim for you.

http://smogsite.com/calculators.html#lambda

[Sampson]

Hi there. I was just sent your way by a couple of forum members, 85Ram50 and Pennyman1. Ive just got hold of an '88 2.0L with about 160K miles on it.
took it in to a test-only station, but they wouldnt even touch it, as it had an after market cat on it with no CA stamp.
I then took it to a STAR garage to have a preliminary smog test done... passed visual/functional, but qualified as a gross poluter at 15mph, with HC at 137 and NOx at 2487(!)
Ive replaced the cat with a magnaflow that has a Dxxx-xxx stamp, and replaced the O2 sensor. I took the EGR off to see if it was crusted up with carbon, but instead saw that it had oil in it (which smelled like gasoline). EGR passed the finger test, but im confused about the oil. Could it be PCV related?
What do you think about those emissions levels? Any thoughts, ideas or suggestions sure would be appreciated!
Thanks from SF!

[85Ram50]

Sampson, I haven't lived in the bay area for more than 10 years but as I recall it the seller has to have passed a SMOG test within 90 days before selling. Did this change or did you not know it? I'm pretty sure the DMV will catch that when you register if the seller still has to pass to sell.

[Sampson]

That hasn't changed 85ram50. But the truck had been sitting unregistered for a few years and the deal was, if I could get the truck up and running, then I could have it.
So I'm trying to figure it out, one part/fix at a time. I'm capable,but not a mechanic so the learning curve is pretty steep!

[85Ram50]

That hasn't changed 85ram50. But the truck had been sitting unregistered for a few years and the deal was, if I could get the truck up and running, then I could have it.
So I'm trying to figure it out, one part/fix at a time. I'm capable,but not a mechanic so the learning curve is pretty steep!

OK I was wondering about that. Good luck then.

[camoit]

If it sat for a long time it could be it has stuck rings and leaking valve seals. Run the piss out of it and check again.

[85Ram50]

I wonder if that oil flush that Geezer101 suggests would work?
I've done it but I don't need smog where I live. Anyway He says to drain the oil and the filter. Put the old filter back on add 1/2 the the amount of new oil suggested (2 qrts) and 1/2 qrt of diesel. Then drive it as normal for a day or so. Then drain it while its warm and put on the new filter and add full amount of oil. He says it fixes valve seals and stuck rings and removes a lot of gunk. I've done it on my Ram50 and my Dakota no harmful effects.

[geezer101]

He says it fixes valve seals and stuck rings and removes a lot of gunk. I've done it on my Ram50 and my Dakota no harmful effects.

It will break down old oil residue inside the engine but it won't fix valve seals. It may 'clean' them out a little and take some of the old oil that has laminated onto the valve stems which might be enough to get them seal better, but when a seal is dead - it's dead. The oil flush is primarily to freshen up the hydraulics first, and then to prolong the life of the new oil by decontaminating the engine as much as possible.

[Sampson]

I definitely appreciate the ideas on how to clean out old crud and oil residue from the engine, and I figure I'll try it, but how likely is that to be the culprit for such high NOx emissions?

[geezer101]

If your piston rings are carbon'd up they will drag contaminated oil up and down the cylinder walls. It affects compression and traces of it will end up in the combustion chambers. Also with the hydraulic lifters/lash adjusters being gummed up this also affects performance/fuel economy (it will reduce valve lift, I am pretty certain of this). I would advise you to do everything practical to clean up the internals of your engine - even run an additive to de-carbon the combustion chambers (but make sure ALL the fuel additive is cleared from the fuel system before taking it in for inspection). Hell, take the air cleaner box off, run the engine with the throttle open and use a water sprayer pump bottle to atomise water into the carb throats and scour carbon out of the engine (this won't wreck your engine - it will be unlikely you can squeeze the trigger fast enough to stall the engine out but even then it will only be temporary) You'll hear the exhaust crackling as flakes of carbon are getting burnt off if the engine is particularly fouled up. Run brand spanking new plugs when you take it in as well. Oh, and install a new coil - a weak spark will prevent a clean combustion burn and this will also have an affect on emissions. Some people have recommended using E10 fuel to lower emissions but I haven't read up on it enough to say if this is legit or a snake oil remedy. We have enough members who have faced the terror of emissions testing and passed so there will be some good advice available.

[camoit]

Seeing you have such high HC tells us it's mechanical. Put a vacuum gauge on the engine and tell us what it's doing. Should be a rock steady needle. If it's whipping around there is a big problem. But I'm 95% sure its a valve seal problem, and, or, a MCA jet problem.
The high NOx is a vacuum leek / lean run. Could be any line and or the booster and MCA jets. It happens when the combustion temp is to high. Clean out the EGR system ports. Also the carb float might be stuck or other ports internally clogged.
You should get the Jet valve delete kit.

[85Ram50]

Thanks for correcting my mistake Geez. I don't want to misinform anyone.

[hutch]

Waiting for California to extend this smog exempt to 1980. :))

[geezer101]

Thanks for correcting my mistake Geez. I don't want to misinform anyone.

That's o.k. Neither of us like to have a fan club with torches and pitch forks :lmao:I should have added to also check the plug gaps and their heat rating. Have you attempted another emissions test yet Sampson?

[Indigo]

Im glad I found this post what Noah says a few posts back is good advice, break up that carbon and put a new coil in to prevent it from building up again. I have an 89 ram that I have struggled with and been unable to get smog legal even with some help from my local ref.
I thought it was Carb related but after reading this I want to try a new coil, do a compression test and clean out the cylinder walls then see if that passes.

[zacatiz]

I have an '85 Dodge Ram 50 with 2.0 G63B engine. I failed Smog today, it passed in every area except for carbon emissions at 25 mph. I needed to get STAR certified smog. I believe the limit is 1.4 units and I came in at a little over 2.

Do you have any recommendations as to a fix? There is a smell of fuel when the car is running that I cannot seem to trace. Should I try and run one of those pass smog additives? Or is carb tuning the wiser option?

[geezer101]

Are all of your ignition components in good shape (leads, plugs, coil etc)? You're getting an incomplete fuel charge burn, that is what is causing high CO readings. Also make sure your engine tune is right, and check for vacuum leaks. Next you can try purging your carb (the jets may be clogged or dirty, causing poor fuel atomisation). Take off the air cleaner, start the engine and try to starve it of air by placing your hand over the throats of the carb. Sometimes it's enough to pull a large volume of fuel up in one hit to clear the jets.

[claych]

???
Pic of the V.I.R. ?(with Noah wins Grace).

[Careyes84]

I failed smog the other day. Here's the cert. Any help would be greatly appreciated.20932
I failed at 15mph but passed at 25mph.

[geezer101]

One or possibly a combo of the following - EGR is clogged up, engine is out of tune, a vacuum leak, O2 sensor isn't functioning properly, CAT converter is bad or the engine isn't cooling properly. High NOx is as of a result of high combustion temps - high HC readings either a vacuum leak or something directly related to fuel mixture control like the O2 sensor or even possibly a clogged primary jet.

[Careyes84]

Thanks Geezer! So, before i smogged the truck and posted this, i had already re-timed the engine (cam was off by two teeth and so was the distro), cleaned and and tested EGR for functionality and it passed, replaced all vacuum lines, replaced O2 sensor with new OEM sensor, and had the Carb tuned by Carburetor Exchange.

Took it to a test and repair facility and they said it was my CAT, Thermostat, and Carbon build up in the cylinders on the pistons. Checked the CAT out, it was deteriorated inside so i had it replaced. Since i have 3 other vehicles, this one is sitting for a little while. Gonna replace the thermostat and use my borescope to check out the cylinders. If they appear to be all carboned up, i'll run a leak down test to see if it affecting the valves seating.

Appreciate all the help fellas!

[mitsubishikid]

another tip for you guys change your oil a day or 2 in advance, before the smog test it will help not having junk in your oil...

[SubGothius]

So my '87 w/ the 2.6 just failed emissions here in Arizona, where they do an idle and 25 mph loaded dyno test. The standard to beat is max. 220 ppm HC and 1.20% CO for both loaded and idle tests. My loaded HC reading of 211 ppm passes, but loaded CO fails at 7.92%, idle HC fails at 1250 ppm, and Idle CO fails at 11.43%.

I'd already replaced the coil and ballast, dizzy cap and rotor, ignition wires, and plugs due to poor running covered in another thread here (http://www.mightyram50.net/vbulletin/showthread.php/7467-1987-Ram-50-2-6L-cuts-out-on-part-throttle-when-cold). I set the static ignition advance at the low end of the stock spec range (5-7 degrees), as I've read less advance can improve emissions at a tradeoff vs. performance. Spark plugs are NGK BPR6EY gapped at the minimum 0.039" (1mm); would expanding this to the maximum spec .043" (1.1mm) help emissions? What else could I try?

[geezer101]

Don't expand the plug gaps, close them. The plugs are gapped from factory to allow a worst case scenario cold start. Try decreasing it 0.5-0.15mm. It will allow a more aggressive/cleaner burn. There a bunch of other recommendations in the smog posts here that should help drop your figures.

[SubGothius]

Hm, what I've read elsewhere indicates there's in inverse relationship between tuning the spark for HC/CO emissions vs. for performance, so what's good for HC/CO emissions is bad for performance and vice-versa, which corresponds to heat being wasted combustion energy that isn't going towards useful work (explosive pressure) -- i.e., a large gap and less advanced ign. timing produces a longer, softer, later burn that produces more total heat to more fully consume the HC in the intake charge, but less explosive pressure and later in the cycle when it's less useful, whereas a small gap and more advanced timing produces a more abrupt, explosive, earlier burn that produces more useful pressure earlier but less heat and thus consumes less of the HC.

NOx is different, as that's a byproduct of heat fusing the oxygen and nitrogen in the air, so more heat produces more NOx. Fortunately, they don't test for NOx around here.

Why retarding spark advance reduces HC emissions (http://nastyz28.com/threads/why-retarding-spark-advance-reduces-hc-emissions.228953/)

"With the maximum spark plug gap, the engine produces minimum hydrocarbon emissions..." (https://www.researchgate.net/publication/313423786_Impact_of_spark_plug_gap_on_flame_kernel _propagation_and_engine_performance)

"Decreasing the gap can make it vulnerable to incomplete burn or misfire." (https://www.eng-tips.com/viewthread.cfm?qid=158647)

[geezer101]

True about decreasing the gap, but that relates equal and opposite of increasing the gap. Gap is too close, not enough ignition area. Gap is too wide, spark is not hot enough. The idea is to find the engine vs sparks' happy place (I have to amend my gap dimensions - it's 0.05 to 0.15 mm less gap :slap:)

[Careyes84]

So a follow to my failed smog...Sorry it took so long.
I replaced my CAT and Thermostat and she's passing with flying colors again. As soon as i find the Smog Cert, i'll post up the new numbers! Thanks again to everyone for their help!

[amsoiltek]

This may be getting a bit off topic but has anyone compared before and after emission test results of switching to a Weber carb from a FBC on Gen 1 Montero?

[pennyman1]

it will fail the visual, and they won't run the tailpipe test in California...

[amsoiltek]

Oh I know it will fail but does the Weber really run cleaner to the tailpipe? Off to do the $1.98 tuneup. Thanks for the input.

[mightymaximus]

I have failed twice now with the V6 mighty max. I attached the two tests to this post. The first test was before the catalytic convertor replacement.
High NOX, is failure reason, but O2 is also high. Tech guesses that my combustion temp is too high, due to lean condtion, and that I might have a vacuum leak, and exhaust leak.
It does run rough before it is warmed up, and has extreme hesitation on acceleration (to the point it sometimes dies when gas pedal is pushed) before warm.
I did lose a tube that goes from passenger side valve cover to the rubber duct right before the intake manifold. I replaced it with a tube I made myself from an old shower hose. The cover side is really tight, but the duct side is just slid in but not a super tight fit. You can see from the picture that the hard inner plastic tube has no barb. Could that be the reason? I will tape the tube to the intake duct, and see if that helps.
(Pictures attached)
There also may be an exhaust leak on driver's side exhaust manifold. Not sure, as oil also drips onto mainfold and pipe from the slow valve cover leak.

Here is the list of things I have done in the recent past as far as repairs go.
* Timing belt broke - replaced it as well as water pump, belt tensioner, front cam seals, and front crankshaft seal
* Replaced serpentine belt at same time as timing belt
* O2 sensor was giving a code when checked with analog meter. Replaced with new one
* Catalytic convertor welded in place by muffler guy (CARB compliant Walker model 80904)
* Exhaust manifold was missing some nuts, so those were installed and existing nuts tightened. Unfortunately sheared off stud closest to driver's side firewall
* Cleaned out PCV valve with B12 Chemtool, didn't seem too clogged
* Mass airflow sensor, and throttle postion sensor replaced a couple years ago
* Spark plugs, wires, and distributor cap and rotor replaced a couple years ago (visually checked plugs right before test, but seemed not very worn, gapped to 40-42 thousandths)
* Computer capacitors replaced per forum instructions

Also, I don't think this engine has an exhaust gas recirculation (EGR) system. Am I correct in that conclusion?

List of problems, that may or may not inlfuence this problem.
* I think my rear main crankshaft seal is leaking
* Something in my manual transmission seems to be leaking clutch hydralic fluid (clutch master cylinder has been replaced few years back)
* Valve cover gasket has slow leak, even though it was already replaced.
It has been a few months since I paid registration, but have not passed smog, so I'm getting nervous that it may get impounded soon (has happened to me before), as this is my only vehicle.

Thanks for any help. This forum's members have really helped me to save lots of money, and saved my sanity a couple times already!:thumbup:

[B-Line]

Several things come to mind. First is the O2 Sensor. You can get a faulty one and it throws off your readings causing the vehicle to run too lean or rich. Second, is one that I have experienced before on another v6 Mitsubishi in the past. Owner had a friend do the timing belt on his car, but afterward he couldn't get it to smog for the life of him, so he sold it at a loss. Turned out the front cam was off by 2 teeth. Car couldn't run right because of that. I fixed the timing and it worked just fine after. Last might be ECU, but lets not go there just yet.

[mightymaximus]

Several things come to mind. First is the O2 Sensor. You can get a faulty one and it throws off your readings causing the vehicle to run too lean or rich. Second, is one that I have experienced before on another v6 Mitsubishi in the past. Owner had a friend do the timing belt on his car, but afterward he couldn't get it to smog for the life of him, so he sold it at a loss. Turned out the front cam was off by 2 teeth. Car couldn't run right because of that. I fixed the timing and it worked just fine after. Last might be ECU, but lets not go there just yet.
Thanks for the reply.
I did replace the O2 sensor, with a walker one just two weeks ago, that had the proper connector already attached, so, it probably is not that.
Also, I was Very, Very, careful to get the cams and teeth lined up exactly right, so I highly doubt that is the problem.

I hope it is not the ECU, but a if you guys know of a place where I could have that tested, or repaired, or purchase a new/repaired one, I'm all ears.
As stated, I did already, recap the ECU, as a preventative measure, and I passed smog once after doing that years ago.

[mightymaximus]

As stated, I did already, recap the ECU, as a preventative measure, and I passed smog once after doing that years ago.
Also, I'm an IT guy with soldering experience, so I was careful when recapping also.

[Chargerx3]

Wouldn’t hurt to pop the ecu and see if everything looks ok still. Might try an extra set of injectors too just in case yours might be failing. Or have them cleaned.

[FMS88]

Also, I don't think this engine has an exhaust gas recirculation (EGR) system. Am I correct in that conclusion?


The V6 does have an EGR system. After 250K miles it may be plugged or no longer operable and that could cause elevated NO readings.

[claych]

....edit see post #63 picture went away:)

[mightymaximus]

The V6 does have an EGR system. After 250K miles it may be plugged or no longer operable and that could cause elevated NO readings.
Ok, here are comparison pics of where my book says the EGR system should be, and what is not there on my engine.
Also, it appears that I have an engine built to federal smog regulations, and not CA as can be seen on my engine under hood sticker.
Perhaps that is why I don't have the EGR system?
If anyone is familiar with an EGR system that is located in a different place, let me know.

I did notice on the pic of the header, to exhaust, that my gasket looks pretty bad. That may be one of the locations I have an exhaust leak.
I believe that the gaskets I need for that joint is the one below.
rock auto gasket link (https://www.rockauto.com/en/moreinfo.php?pk=1080710&cc=1430280&jsn=885&_nck=ZExt1ysfqhqWnq%2BEvUNdS3Txyey60IDtnjPWF5UU9J0 BWQv7pvqZbkEUk86%2BAYIh8MwADrWeNyYtbtSs7Y5B3bA%2FN ykLpqgBQEkvFHVFWtyvUhetnVhnUi49wPvDpyAxWkI%2BJphA3 vyckpLgdgD%2BDJRJZciBU7ME5zM6xRSiipr%2FtCrmh9bIEwT wwzmAavYpnWUbh%2FdtBlGU5LWWpzOKfWwwQAEP89W1S05yrsA t8dqEG0hOUP5QRPzsXrzZl9a9wmrGrmNtXo6PoEkOLb1%2BHIz AVNk25G2OYUvRhElzYwdcQe4vfqeSxJQ7InmOF%2Fhtj%2BqBX mMqyfA080s21hBhwNQZ5XwUN%2FVn)

If anyone knows a good mechanic that is in the San Diego county area, that works on our older vehicles, I'm willing to take it there, if he/she can fix it. Just went to a place that said they wouldn't fix smog related issues, seemed kinda strange thou:shrug:

Thanks again!

[mightymaximus]

Wouldn’t hurt to pop the ecu and see if everything looks ok still. Might try an extra set of injectors too just in case yours might be failing. Or have them cleaned.

I know that cleaning injectors, usually involves running the cleaner through the fuel rail on newer vehicles. Do our trucks have the port where we can attach a pressurized cleaner can onto the fuel rail, or is that something done with specialized eqipment that requires removal of the injectors?

[B-Line]

You clearly dont have the EGR System on yours.

[Chargerx3]

Typically you pull them and send to a lab to have cleaned and balanced. Other cleaners are marginal especially in a short amount of time.

[claych]

https://i.stack.imgur.com/mGuZD.jpg
The above has been around for a long time ,posting here to help Folks understand 5 gas interaction.
Looking at the 2 V.I.R's & the mentioned severe stumble...
Have You replaced the fuel filter? I would also perform
fuel pressure and leakdown tests.
Granted, the injectors could be suffering from poor spray pattern
and solenoid wear, but hey simple (cheap) stuff first !!

[mightymaximus]

Have You replaced the fuel filter? I would also perform
fuel pressure and leakdown tests.
Granted, the injectors could be suffering from poor spray pattern
and solenoid wear, but hey simple (cheap) stuff first !!

I did replace the fuel filter a few years ago, as well as drop the fuel tank to check out fuel pump. The tank was super clean.

I will have to get the tools to perform a leakdown, and fuel pressure test.
It seems a lot of the mechanics in SD, don't want to touch my truck as they can't see high dollar repairs coming from me.

If I was back in Nevada, I could just ask any number of friends, and take my time fixing it. Here in CA, it feels like the green police are hiding behind every corner to penalize those who don't replace their older vehicle for a Pruis.
Thanks again for the suggestions.

[claych]

Your Welcome!
Also forgot to mention,(sorry), replace that 'shower tube' with a correct size piece of vacuum line.
-The loose fitting is a potential area for 'unmetered' air - read not 'seen' = no signal to ecm= no inj
pulse width increase net result lean mixture.
And,
Repair all exhaust leaks !!! -any- exhaust leak will dilute the machine sample, simply put, sample is lean
Engine is not running lean.
Finally,
Change the fuel filter!!!:)
P.s,
Might be worth a few calls to Your buds in NV( tools etc)

[mightymaximus]

OK. I'm trying to figure out how I am supposed to hook up a gauge to the fuel rail to test fuel pressure. Usually there is a port to screw onto the fuel rail to test it. I don't see that on the 6G72 fuel rail.
Do I need a special tool, that I can put inline with the fuel line or fuel rail to give me a testing port?
Thanks again.

[mightymaximus]

Did a compression test because I already had the tester.
All cylinders in between 150-160 psi
1 and 4 - 150
3,5,6 - 155
2 - 160
As soon as I can figure out where to hook up the fuel pressure tester, and borrow or buy a compressor, I'll give results of the fuel pressure, and leakdown tests.
Can I attach a fuel pressure tester to the high pressure side that I pointed to in the attached picture, with a kit, or adapter?
Thanks again.

[Chargerx3]

I don’t know of a check valve in the line.

[claych]

I'm trying to figure out how I am supposed to hook up a gauge to the fuel rail to test fuel pressure. Usually there is a port to screw onto the fuel rail to test it. I don't see that on the 6G72 fuel rail.
Do I need a special tool, that I can put inline with the fuel line or fuel rail to give me a testing port?
Thanks again.

MD998700
MD998753

Make sure You use a fuel pressure gauge with provision to purge air___

[mightymaximus]

MD998700
MD998753

Make sure You use a fuel pressure gauge with provision to purge air___
@claych
Thanks for those part numbers.
I borrowed a gauge from Oreilly's, and realized that it has no adapter for a mitsu.
Attached is a picture from an ebay listing of the parts needed.
Unfortunately they want $70 for it.:shock:
If anyone has another place they have found that part for cheaper, or has one they want to sell, let me know.

I may just take it to a shop to have the fuel pressure tested as it may actually be cheaper that the adapter. I talked to a friend who also has a early 90s truck about shops he goes to in SD area.

[mightymaximus]

So, I took my truck in and the mechanic had a hard time diagnosing what was the problem as he doesn't see a lot of mitsubishi engines these days.
It tripped a code, which he could not read as he had no analog volt meter, or OBD 1 scanner. As I left the lot the check engine light went off.
That was the first visit, for which there was no charge.

The next visit was set up with a guy the owner called in that travels all around the county whom specializes in diagnosing hard to figure out vehicles.

He says it was my mass air flow sensor. He could also read the history of the code that tripped and disappeared on the first visit, which was a MAF code. Admittedly, I replaced the original failing MAF with pretty much the cheapest (~$100) remanufactured one I found online two years ago so I could potentially pass smog, which I did.

They also said their is not really a reliable way to test if the remanufactered MAF is good outside of getting one and installing it, and running it on the dyno to see if the ECU responds as it should. Also they have not had consisent results from remanufactered MAFs. Some are DOA, some work for a while, some a little longer. Is that really the case?
Is there a remanufacturer that tests their MAFs before shipping them out?
I believe the one I bought only had a one year warranty, but I'll double check, and post the one I bought for future members to see.

Now that it has apparently failed, do you guys recommend a certain brand of remaufactured MAF, that has shown to be better than another?
I can't justify spending the nearly $800 dollar price they want to charge just for the new Mitsubishi original part. Especially since I have so many miles on this engine.
Thanks again guys for all the help.

[geezer101]

Found OEM direct replacement new units retailing from about $50 - $200 USD. $50ish are Chinese made on ebay/ $200ish made by Beck Arnley on CARid and Summit Racing. There is always the chance the parts are all coming from the same manufacturing plant and are just jammed in different boxes (happens all the time). For $50 you don't have a lot to lose by trying one out -

https://www.carid.com/1994-mitsubishi-mighty-max-mass-air-flow-sensors/

https://www.summitracing.com/search/make/mitsubishi/model/mighty-max/brand/beck-arnley/price-range/100-250/part-type/maf-sensors

https://www.ebay.com/itm/MASS-AIR-FLOW-SENSOR-METER-MAF-FOR-Mitsubishi-3000GT-COLT-GALANT-MIGHTY-NEW/332248356981?fits=Model%3AMighty+Max%7CMake%3AMits ubishi

If someone has some insight to the MAF situation they'll chime in one thins one. Hope the links are helpful.

[Chargerx3]

Go to the junk yard and find one for cheap. Most have a 30 day return policy.

[mightymaximus]

Found OEM direct replacement new units retailing from about $50 - $200 USD. $50ish are Chinese made on ebay/ $200ish made by Beck Arnley on CARid and Summit Racing. There is always the chance the parts are all coming from the same manufacturing plant and are just jammed in different boxes (happens all the time). For $50 you don't have a lot to lose by trying one out -

https://www.carid.com/1994-mitsubishi-mighty-max-mass-air-flow-sensors/

https://www.summitracing.com/search/make/mitsubishi/model/mighty-max/brand/beck-arnley/price-range/100-250/part-type/maf-sensors

https://www.ebay.com/itm/MASS-AIR-FLOW-SENSOR-METER-MAF-FOR-Mitsubishi-3000GT-COLT-GALANT-MIGHTY-NEW/332248356981?fits=Model%3AMighty+Max%7CMake%3AMits ubishi

If someone has some insight to the MAF situation they'll chime in one thins one. Hope the links are helpful.

Ok, through some research, I have found that the part sold on carid, is also sold, by Napa, and available from multiple sellers on amazon.
Here is the Napa link:
https://www.napaonline.com/en/p/NECXTP460006?partTypeName=Mass+Air+Flow+(MAF)+Sens or&keywordInput=mass+air+flow

Here is the Amazon link:
https://www.amazon.com/Cardone-74-60006-Remanufactured-Airflow-Sensor/dp/B000C46Y22/ref=sr_1_1?crid=TAWX2RFUT7N5&keywords=cardone+mass+airflow+sensor&pd_rd_r=2d86e76c-44af-42ff-b589-97833515e7ed&pd_rd_w=bqaoS&pd_rd_wg=BXwIn&pf_rd_p=9e334aac-d5e5-42f4-99b3-257ad129944e&pf_rd_r=JGJ5FX54AP64Q4S51SE6&pid=Yx4osRo&qid=1573774234&sprefix=cardone+mass+air+flo%2Caps%2C212&sr=1-1&vehicle=1994-72-935-20-34---8-862----294-180-&vehicleName=1994+Mitsubishi+Mighty+Max

I happened to look at the 'other sellers' that are listed on the amazon product page, and found an open box one for $33 bucks.
I figured I'd roll the dice, as this is even cheaper than the junkyards wee listing their MAF.

Here is the link to the one I bought last year around July. Not good buld quality. It didn't even last a year, but I didn't try to get a warranty replacement as this Jun was around the time the timing belt broke, and I was not sure if I was going to keep the truck.
https://www.amazon.com/gp/product/B01N2LB2WH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Just in case I have a bad wiring harness going from the MAF to the ECU, I'm going to check if my Chilton manual has a wiring schematic to see if I have any wiring issues. I don't believe that the mechanic tested the harness from MAF to ECU, because I didn't see him take out the ECU.

Thanks again for your help. I hope this helps someone else.

[mightymaximus]

Go to the junk yard and find one for cheap. Most have a 30 day return policy.
Unfortunately nearly all of the junkyards in San Diego are right next to the border, so there is potentially people from two countires pulling parts. When I called a few junk yards they said the MAF is usually one of the first things pulled.
I may still go down there if my reman MAF doesn't pan out, or if I find I need a replacement wiring harness.

Oh and I forgot to mention that Amazon would not ship the MAF here, likely because CA thinks the lead will jump off the circuit board and crawl into my skin killing me instantly, or something to that effect:stupid:

[geezer101]

The problem with used sensors etc is they are potentially the same age as what you're trying to replace and it is a gamble that, even if you do find a suitable unit, it's not going to be as bad as the one you already have - with the added bonus of driving to the yard, messing around removing it after walking around for half an hour finding one. I wonder when CA is going to ban smoke detectors due to their radioactive isotope content and it taking 400+ years to break down...

[Chargerx3]

Op has access to pick n pull they have a 30 day return guarantee. I’ve purchased dozens of Mitsubishi mafs and never had a problem with one. They are the 91’+ units. OP likely has one of the few that do go bad. Either way he has 30 days or longer if he buys the extension to take it back. Walking the yard isn’t difficult either. They organize thing quite well and label their rows.

[mightymaximus]

Good news mini-truckers!
The $33 dollar Cardone reman MAF worked great, and ended up cheaper than the drive down to the border, and the $50 they wanted at the junk yard.
On the first drive after getting it swapped out, I immediately noticed the increase in low end power, and the tail pipe emissions were no longer excessively smoky.
When I got to a parking lot I noticed it still seemed to miss every so often. After I returned home I popped the hood with the engine still running, and what did I see?.....:shocked: an electrical arc from the 6th cylinders spark plug wire boot to the metal surrounding the spark plug wire. I turned off the engine and reseated the cable, still arced. I found the old, original cables, got an appropriate sized one, installed it, and it did not arc, and fixed the missing, and cleared up the exhaust even more.

If I had not looked at night, if I would have noticed the spark? After finding it, I noticed that their was a distinct noise made by the arc. I will remember to listen for that in the future when an engine is running rough.

I wonder how long that cable was bad, and will be testing all the cables to make sure they are within spec.
As you can see in the test results, there is quite the difference in what came out of the tailpipe this time!:thumbup:

I'm glad the mechanic was able to steer me in the right direction, and grateful for everyone's suggestions. What a load off my shoulders:partydance:

Now I don't have to drive around always looking over my shoulder :policered:, or worrying I will get a parking ticket, which are $52 bucks a pop here.

BTW, does anyone know if there is any place that buys the old MAFs beside turning it in as a core,since the last two I got had no need to trade them in as a core?
I'm tempted to tear into the original Mitsu one and see if something simple failed, like a cap, or easily replaceable chip, so I could possibly have a spare.

[geezer101]

Nice win on all fronts. That spark at least confirms your ignition system is pretty healthy + the low HC reading in the emissions test means it's burning everything about as cleanly as it can.

[bigwavedave]

Hey everyone. I am brand new to this forum and this is my first post. I've got a 1989 Mighty Max with the G63B with 167xxx in it that will not pass CA smog. After it failed its first attempt, I replaced the CAT, muffler, 02 sensor, plugs (gapped to .43), wires, distributor cap, changed oil and filter, pulled the EGR and cleaned it ( it wasn't clogged, but a bit wet/oily looking), ran sea foam spray through the carb, and have been running 91 octane in it and drove it about 200 miles to hopefully clear the system out of any old bad crap. I've hooked up a vacuum gauge and the gauge reads that the engine is healthy. After doing all this, I took it to get a retest and was confident it would pass, but it failed again! And some of my numbers were worse than the original test, WTF! I've attached images of both test results. Thank you for taking the time to read and any inout would be much appreciated!
23722

23723

[geezer101]

Did you swap the ignition coil? If it's weak, that will affect HC readings from not the air/fuel charge being burnt efficiently and in turn affect CO2 and other readings. An ignition coil typically lasts about 10 years before it starts to break down. Also, how hot was the engine when you got it into the testing station? The CAT works best when it's hot. Another thing - have you ever flushed your engine oil? Even with an oil change, there will be residual contaminated oil in the engine. The '89 engine should be a hydraulic head and if the hydraulic lash adjusters are gummed up, it will affect combustion chamber fill from a reduction in valve lift. Not sure what else to reccomend. The carb may also be overdue for a rebuild...

[bigwavedave]

I swapped out the coil today. I'll flush the oil in the next few days as well. When I got the second smog test, it was only about 2 miles down the road and the truck wasn't that warm, think that could have any affect on the second test results?

[geezer101]

From what I've looked up, the CAT works at it's most efficient when it is hot. One tip I found was to keep the engine running until it gets called in for testing in an attempt to keep the CAT hot. Your NOx readings look...extremely low (if I'm reading the report right) so that would indicate your mix isn't lean, the EGR is working properly along with the CAT and your engine temps aren't abnormally high. Having the engine at full operating temp will help as well. You swapped the plugs - you may need to consider trying either a performance plug or a plug in a higher heat range to fudge the numbers. Also try 'purging' the carb by taking the air filter off, opening the throttle at the linkage while placing your hand over the throats in an attempt to starve the engine of air. The sudden massive increase of internal vacuum might clear possible partial blockages in the jets and improve atomisation, which in turn should aid a cleaner air/fuel charge burn. A can of carby clean wouldn't hurt either. Not sure of what else I can suggest. Hopefully either another member will add their opinion to this and the next time you have to jump through the emissions testing hoop you'll pass.

[bigwavedave]

okay right on Geezer I'm going to give those things a try!

[parkedufo]

Hi everyone, I bought a 94 MM and having trouble getting it to pass smog (live in San Diego, CA). So far I've changed the rotor cap, cleaned the EGR, had the EGR pressure checked that was fine, even went and bought to bottles of guaranteed to pass (did not pass). I found out I also need to take it in to see a referee, love that. I was wondering if anyone has had any experience with refs? Sick of looking over my shoulder because I can't even get a title transfer unless I have a passing smog check.

[geezer101]

Are the O2 sensors working, what is the catalytic converter like condition wise etc? See if there are any error codes lurking in the ECU and correct any detected faults. There are all sorts of things that can affect a smog test. Even dirty or contaminated engine oil can be enough to barely cause it to fail. Use the lowest octane fuel you can get (85) and don't use any fuel additives (seafoam will clean out the upper combustion, but the solvent residue will insta-fail it), oil flush the engine to scour as much old oil sediment out of the block and sump. Don't disconnect the battery for at least a week before taking it in for an inspection or the ECU will be re-learning base tune and it'll throw it out of emissions specifications. Even have a crack at cleaning your injectors out so the spray pattern is uniform.

[xboxrox]

Hi everyone, I bought a 94 MM and having trouble getting it to pass smog (live in San Diego, CA). So far I've changed the rotor cap, cleaned the EGR, had the EGR pressure checked that was fine, even went and bought to bottles of guaranteed to pass (did not pass). I found out I also need to take it in to see a referee, love that. I was wondering if anyone has had any experience with refs? Sick of looking over my shoulder because I can't even get a title transfer unless I have a passing smog check.


NO SMOG tests in Hawaii (yet) but this stuff helped my truck run better: https://www.oreillyauto.com/detail/c/cataclean/chemicals---fluids/maintenance-chemicals/fuel-system/fuel-treatment/dfc494044694/mr-gasket-cataclean-16-ounce-fuel-additive/mrg8/120007

I closely followed the directions; do they tell you the reason for SMOG fail ? Would googling the reason give a fix answer ?
Good Luck

[camoit]

What was the test results?
most of the time the cat goes bad.