1985 Dodge Ram50 non-start issue

[Reluctant_Rabbit]

Long time lurker, first time where I'm stumped to the point I needed to register and make a post.

This is my 1985 Dodge Ram 50, California emission 4G63B (G63B) manual 2wd truck.



I bought it a few months ago for $400 needing some carb cleanup and vacuum/pcv lines finished as some kid slapped a weber 32/36 on it and didn't know what they were doing to finish it. After getting it running decently, it's been a solid work truck up until last week after a 400 mile excursion all around the bay area picking up parts for another headache project of mine. Literally backing up into my driveway, it gave up the ghost.



At first I thought it was a fuel issue, or maybe too low of compression (i'd be lying if I said the compression numbers on the engine are great, and that it doesn't consume oil) However reading another post that I can't seem to find here on the forums, someone made mention of very similar symptoms.

I believe I have weak spark/dead ICM. Fuel pressure is great, new pump, holley regulator, clean genuine weber 32/36, pressure set smack at 3.1PSI. Timing didn't jump because every once and awhile it will crank to life, maybe it'll idle and then act like it floods out, or other times you can rev it up but when it comes back down to idle it back fires and dies taking quite a bit of effort to get it to restart.



https://youtube.com/shorts/eH0Wckda2mQ?feature=share

https://youtube.com/shorts/qMZ7inmYPk8

I saw a post earlier with someone having the same symptoms and it boiled down to a bad distributor. Looking for others opinions as I've pretty much thrown the parts cannon at everything else that could have been bad. New coil, new ballast, plugs, wires, cap and rotor, aforementioned fuel pump and regulator, etc.

I also had a question as to what the ECM on these things is for, and I grabbed a spare from a junkyard that I yoinked nearly an entire interior for my truck yesterday just in case that could also be part of my problem.

Any help would be greatly appreciated, as I do use this truck all the time for mobile mechanic work and hauling small loads around for people. The HOA has not been a fan of it being dead in my driveway.

[Fingers]

As far as I was told, the ECM has nothing to do with the ignition system. It only ran the Mikuni carb. I still haven't removed my ECM just in case I was informed incorrectly.

BTW, how do you get away with a Weber in California?

[Reluctant_Rabbit]

I don't, lol. I usually register my cars out of Michigan, and this one is soon to follow that path.

[SubGothius]

Pretty sure the ECU only manages the Mikuni carb feedback systems, so it does nothing with a Weber.

The ignition has its own ICM, mounted inside the distributor and integrated along with the coil trigger sensor as a single unit.

[camoit]

Check the Coil. The spark gets weaker the older it gets. Think of it like a penis. LOL

[Fingers]

They got blue pills for coils?

[Reluctant_Rabbit]

Update: a new distributor did fix the truck! Runs great once again. https://youtu.be/ooh-D-Qv-VE
Now to get the interior installed this weekend.

[xboxrox]

Update: a new distributor did fix the truck! Runs great once again. https://youtu.be/ooh-D-Qv-VE
Now to get the interior installed this weekend.

Good Job R_R..! Am wondering the distributor source..? Thanks for posting & red is my favorite color especially on MM or Ram50...

[Reluctant_Rabbit]

Napa was able to order me one from Cardone, but it set me back about $300 to be real with ya’

[xboxrox]

Napa was able to order me one from Cardone, but it set me back about $300 to be real with ya’

Thank You X2

[Reluctant_Rabbit]

Update: back to square one. Crank no start/erratic fire. Spark from the coil is definitely good, but seemingly weak from the plug wires.

[Reluctant_Rabbit]

Another update: Switched over to an MSD Blaster 2, truck runs again but now I'm not sure where to dial the ignition timing into. No matter where I seem to move it, the truck isn't very happy.

Plugs are NGK BPR6ES gapped at 0.044
Plugs wires, cap, and rotor are all new
Distributor is new

I just seem to be stumped, can't get it to run right, sounds like a bag of popcorn in the microwave.

[xboxrox]

Dang that Sux..!

CHECKLIST:

Compression
Spark (test with real spark plug on wire end)
Valve & Ignition (initial, vacuum & mechanical) timing
Fuel supply (pressure & clean & fresh)
Carburetor (float adjustment & leak test & idle air fuel adjust & properly jetted)
Vacuum leaks
Engine fasteners tight (cylinder head, intake & exhaust manf and carb)

Reference FSM & Tech Manual's Troubleshooting Charts

Hope you find the problem soon...

[1fastcolt]

have you checked to make sure the timing is dead on.. might of skipped a tooth or 2... it would still start but moving the dist wont change how it runs when this happens.

[xboxrox]

Distributor might be one tooth off ?? Put the #1 piston TDC and verify the rotor is pointing @ #1 wire or slighty advanced...

[Reluctant_Rabbit]

Distributor is definitely in the right position, haven’t verified if the belt jumped

[xboxrox]

Thumb over the #1 spark plug hole as the piston is moved to TDC on compression stroke will tell if the valves are timed ok... It will blow your thumb off the hole...

[Reluctant_Rabbit]

Three months after the original post, I've finally pinned down what my intermittent run issue. My truck decided it wanted to have VVT! Now the trouble is actually trying to source the cam gear. If anyone has a 4G63B 2.0 Cam gear I've got paypal/cashapp/venmo ready to go.

[Gremlin50D]

I wonder if this one would fit it's from a newer G63B? I belive but when I get the chance I will look threw the parts engines I have and see if I have a spare that's usable but I have also heard they make a adjustable cam gear for our engines but I've yet to find one unless someone else here knows of a alternative.
https://www.ebay.com/itm/32569607227...mis&media=COPY

[1fastcolt]

I wonder if this one would fit it's from a newer G63B? I belive but when I get the chance I will look threw the parts engines I have and see if I have a spare that's usable but I have also heard they make a adjustable cam gear for our engines but I've yet to find one unless someone else here knows of a alternative.
https://www.ebay.com/itm/32569607227...mis&media=COPY

I dont think that one is correct.. in my opinion its way over priced.. its from greece so it will take along time to ship and if incorrect part it would be hell to return... plus the post says crankshaft gear... its a camshaft gear.. plus to me the FR written on it means front right which indicates 2 gears this being the right side... I could be wrong.. but this is just my opinion on that post..

[Gremlin50D]

Well I dug more and more ran some part numbers found this site https://www.mitsubishipartswarehouse...w0LWdhcw%3D%3D looks like any cam gear.from a 1.5,1.6,1.8,2.0,2.4 will bolt up being OTR driving I can't just order a bunch and try atm but.you can find adjustable cam gears for other SOHC 2.4,1.5,1.8 engines for pretty cheap on cheapbay might be worth looking into.