No power

[Merg]

Good morning! So I just purchased a 1992 power ram 50 4x4 and am having some issues. The truck starts and runs and idles fine after warming up but has very little power. It will backfire a little bit and when you push the throttle down, it just feels like there’s nothing there. It will eventually get up to speed and drive fine but I know it should have more power. At first I was thinking idle air control valve but after a little digging, it doesn’t seem like these trucks have one. Could this be a vacuum issue?

the previous owner said that he put a new head on it and replaced a bunch of sensors. He said it ran perfectly for about 8 months and then it started doing the backfiring and feeling like no power. If you feather the throttle, it will drive but if you try to get into it to accelerate to get into traffic, it’s got almost nothing.

I am a Yamaha outboard tech and am pretty familiar with engines in general but I wanted to ask some of y’all before I just started buying parts to throw at it. Any help at all would be much appreciated.

thanks!

[Merg]

It is a 2.4l with multi port injection.

[Law Dog]

Fuel check? Water or plugged filter maybe?

[1fastcolt]

sounds more like a timing issue with the backfiring... check plugs and timing.

[Merg]

Does this engine use a vacuum advance system?

[camoit]

You should look through this thread to start going down the list of common problems. I always say start with the fuel filter and go from there.
http://www.mightyram50.net/vbulletin...and-do-it-ASAP

[Merg]

I have gone through most of the items on that list. Plugs and wires, oil, etc.. I ordered a new MAF sensor and a new coolant temp sensor. I’ve checked the timing and firing order. Still has a backfire and still has almost no power. Is there a way to swap this injection system on the 2.4l for a carburetor?

[tortron]

A lot of people miss this when they set timing on these engines
Screenshot_20230321_082604_com.google.android.apps.docs.jpg
Screenshot_20230321_082936_com.google.android.apps.docs.jpg

[camoit]

Put a vacuum gauge on it and see how wildly the needle moves. It might have bad Jet valves

[Merg]

The truck was running perfectly for 6-8 months after a new head was installed and then it started doing this backfire/no power this all of a sudden. I don’t believe it is a timing issue since it ran so well since timing was last set. I ordered a MAF sensor and a coolant temp sensor. They should be here today.

[xboxrox]

Hello Merg

Sounds like what my truck was doing even after installing a new non jet valve cylinder head ~ my truck has (had) two catalytic converters now the plugged one is gone ~ truck runs better although sometimes it still acts odd when accelerating in 2nd gear from a low RPM (surges like it needs fuel?)

MAYBE CHECK:

Catalytic Converters & exhaust system for plugging
O2 sensor / sensors
Air Inlet Temperature sensor
Air & Fuel filters (like new is best)
Vacuum leaks
Fuel Injectors test
Intake & Exhaust manifolds (check fasteners missing & tightness)
EGR system check operation
PCV check
Computer ECM PCM whatever it's called (try test driving with a replacement ECM PCM)
Wiring Harness Connectors (clean & remove any silicone)
EDIT: Do a compression test

I would not recommend a carburetor swap ~ I bet eventually you will accomplish the FIX ~ these trucks are old & will show age in looks and performance, it's not a Tesla
Best of Luck

[Law Dog]

Did you ever pump fuel into a clear jar and let it settle for a while? Could be as simple as bad gas?

[Merg]

Hello Merg

Sounds like what my truck was doing even after installing a new non jet valve cylinder head ~ my truck has (had) two catalytic converters now the plugged one is gone ~ truck runs better although sometimes it still acts odd when accelerating in 2nd gear from a low RPM (surges like it needs fuel?)

MAYBE CHECK:

Catalytic Converters & exhaust system for plugging
O2 sensor / sensors
Air Inlet Temperature sensor
Air & Fuel filters (like new is best)
Vacuum leaks
Fuel Injectors test
Intake & Exhaust manifolds (check fasteners missing & tightness)
EGR system check operation
PCV check
Computer ECM PCM whatever it's called (try test driving with a replacement ECM PCM)
Wiring Harness Connectors (clean & remove any silicone)

I would not recommend a carburetor swap ~ I bet eventually you will accomplish the FIX
Best of Luck

why would you not recommend a carb swap? I am an outboard technician and am very familiar with carburetors.

[Merg]

Did you ever pump fuel into a clear jar and let it settle for a while? Could be as simple as bad gas?

I haven’t but the way I am able to make the conditions change by unplugging sensors and capping vacuum lines makes me believe it isn’t bad fuel but I am going to siphon some out of the tank when I get home from work. The new MAF sensor and coolant temp sensor arrived today.

[Merg]

Should you be able to hear the fuel pump come on when you turn the key to the “on” position?

[xboxrox]

Well, because if you cannot FIX what's there now; what makes you think a carburetor will FIX it..?

Try another PCM ECM whatever the computer is called ...

[Merg]

Well, because if you cannot FIX what's there now; what makes you think a carburetor will FIX it..?

Try another PCM ECM whatever the computer is called ...

well, because with a carbureted motor, those sensors are obsolete……. Also, I like to weigh all of my options before making a decision on what route to take. I have been turning wrenches for 18 years, this is just an unfamiliar engine and electrical system. I am here to gain some knowledge on these vehicles. I will FIX what is here. I am just asking some questions, if that’s ok with you?

[xboxrox]

I feel embarrased

[finalfighter]

check the ecm. they commonly fail do to leaking capacitors.

[Merg]

check the ecm. they commonly fail do to leaking capacitors.

I just grabbed an ecm from the pick-n-pull yesterday. I’m going to put it in this afternoon and check it out.

so far what I’ve done is:
-plugs & wires
-distributor cap & rotor
-coolant temp sensor
-MAF sensor(brand new defective)
-drained fuel & replaced fuel filter
-checked timing
-removed and inspected fuel pressure regulator
-tested fuel pump(turns on and is pumping)
-checked and/or replaced all vacuum lines

the next items on my list to check:
-ecm
-injectors
-cp sensor
-crank sensor
-O2 sensor

if anyone can think of anything else that I should look into, please let me know.

[Law Dog]

Fuel pump relay did you try that? The Gold relay next to the ECU.

Ill tell you what I have been going through maybe you can get something out of my mess. Bought a nice 91 D50 3.0 A/T not running it came with 2 fried ECUs. I sent both in to get rebuilt but they could only fix one of the 2, one was toast.

My AIC on the throttle body was stuck that’s what was frying the ECU change yours out before trying that other ECU! So my ECU came back rebuilt I put on a new AIC and it ran but the fuel relay buzzes all of the time except when it was running even with the key off the battery cable had to be taken off of the battery to keep from draining the battery.

Tried a new relay same same so I’m waiting on another rebuilt ECU to try to help eliminate that if it’s not the problem. I have a 10-15 second delay before the buzzing starts not sure why the delay. I did send my rebuilt ECU back but no change when I got it back.

[xboxrox]

This stuff makes me understand why some folks go the Weber route..! Installing a new non jet valve cylinder head stopped the using coolant & oil BUT truck still has a slight miss 50% of the time ~ using more accelerator stops the miss ~ I should remove the top of my Mikuni carb and inspect ~ it sat sideways and was banged around some when doing the head... Hope to never buy another motor vehicle again...

Good Luck getting it Fixed
George

[Merg]

Good morning! So I just purchased a 1992 power ram 50 4x4 and am having some issues. The truck starts and runs and idles fine after warming up but has very little power. It will backfire a little bit and when you push the throttle down, it just feels like there’s nothing there. It will eventually get up to speed and drive fine but I know it should have more power. At first I was thinking idle air control valve but after a little digging, it doesn’t seem like these trucks have one. Could this be a vacuum issue?

the previous owner said that he put a new head on it and replaced a bunch of sensors. He said it ran perfectly for about 8 months and then it started doing the backfiring and feeling like no power. If you feather the throttle, it will drive but if you try to get into it to accelerate to get into traffic, it’s got almost nothing.

I am a Yamaha outboard tech and am pretty familiar with engines in general but I wanted to ask some of y’all before I just started buying parts to throw at it. Any help at all would be much appreciated.

thanks!

UPDATE!! It’s fixed! So it was a combination of a few things that was causing all of the intake backfire and no power issues. First, I removed all of the emissions parts. Vacuum lines, charcoal canister, EGR and capped everything. Which made the rich running condition stop. Then, I used my timing light to find that the ignition timing was firing before the intake valve could completely shut, causing the fuel mixture to detonate allowing the combustion to push back into the intake manifold. So I loosened the 12mm bolt holding the distributor and rotated to the highest rpm I could get and then adjusted the idle back down. She’s running like a champ now. No more popping and normal acceleration power.

[xboxrox]

That's Cheating !!

[Merg]

Fuel pump relay did you try that? The Gold relay next to the ECU.

Ill tell you what I have been going through maybe you can get something out of my mess. Bought a nice 91 D50 3.0 A/T not running it came with 2 fried ECUs. I sent both in to get rebuilt but they could only fix one of the 2, one was toast.

My AIC on the throttle body was stuck that’s what was frying the ECU change yours out before trying that other ECU! So my ECU came back rebuilt I put on a new AIC and it ran but the fuel relay buzzes all of the time except when it was running even with the key off the battery cable had to be taken off of the battery to keep from draining the battery.

Tried a new relay same same so I’m waiting on another rebuilt ECU to try to help eliminate that if it’s not the problem. I have a 10-15 second delay before the buzzing starts not sure why the delay. I did send my rebuilt ECU back but no change when I got it back.

the gold relay next to the ECU is the ECU relay, not a fuel pump relay. Although, if that relay has gone bad, the fuel pump probably won’t turn on because the ECU will have no piwer going to it. You can check to see if the fuel pump is working by jumping 12v+ to the white test plug on the passenger side of the engine bay. It is right next to the timing ground pin(brownish color).