I'm somewhat new to the forums, but what a great resource for Ram Van owners. I'm really hoping somebody can point me in the right direction with this problem I've been having with my van. It's a 1989 B250 Conversion, 318 5.2L. This is the first winter I've owneditand the engine has been acting funny in this cold Minnesota weather.

If I start the van after letting it sit for a few days the engine will start fine and Ishift into drive, but whenI give it some gas the engine will stutter, backfire and die.At that point I have to shift into park, start it again, shift back into drive and contine moving until the engine dies again. This usually goes on for a few minutes until it's warmed up and quits the dying cycle.

However even when the engine is warmand I amaccelerating, it will still sometimes hesitate for a few seconds and then backfireORIt will stutter for a few seconds, then bolt forward at full throttle, both scenarios are undesireable. Occasionally it will also backfire after giving it more gas even at highway cruising speed.I should also say that when I say backfire, I mean a loud bang from inside the doghouse, a friend who drove it with me said that was a backfire.

I'm new to large van mechanics and would really appreciate a shove in the right direction. Please let me know if I should clarify anything I said.

thanks,
Michael Bishop

 

You don't say, but I'm thinking your last vehicle was fuel injected. The van is carborated, and in cold weather gas doesn't atomize as well, at least until the throat of the carb warms up to help keep the vapor state. The hesitation at sudden acceleration may be because of this, or a partially plugged fuel filter. Does the hesitation go away as the engine system warms up...say after 30 minutes of driving?

The backfiring is a symptom of either timing adjustment or too much gas.- Check cap, rotor, plugs, and wires. I only see an issue on my 87 in the winter myself. (I'm in Upstate NY)

It sounds like you choke is working properly because you have a good start, but it might be staying closed a bit too long. Try using some carb cleaner. Admittedly this in the winter isn't a fun task since to do it, you need to take the doghouse off and run the engine. You also need to take the air cleaner cover off. I also suggest, for safety sake, taking the filter out as well since it can get soaked with carb cleaner and makes a nice candle if it catches a backfire just right - I know this from experience though I was using the more flammable starting fluid at the time. Dress for a 20 mph wind -- the fan on the front moves a lot of air and all of it is cold!

You can try warming it up by idling for longer before driving, and that should help with the stalling.

You may also notice a tendency to diesel a bit when you shut it down That means that some gas has gotten into the cylinders and is combusting without a spark, but with heat and compression similar to a diesel engine..

 

Considering that the problem also exists when the engine is warm, I'd start looking at the accelerator pump as the problem.

 

Thanks for the responses guys. It's been far too cold to work on the van these past few weeks and I think we're going to take another crack at it this weekend. My friend who has worked on a lot of Ram Vans belives it is a faulty EGR unit causing the backfire. Does this seems logical and would this also cause the engine dying, or do I have two seperate problems?

 

A faulty EGR can cause stalling or rough idling but it won't cause backfiring.

 

i know this might be a little late but my suggestion to you is check the timing of the thing first, and as far as it being carburated Igadget's wrong, it is feul injected with a TBI(throttle body injectio system) its right underneath your airfilter housing(which kinda looks like a carb) tear that thing off and you can see the two black caps for the injectors...

 

A buddy of mine ordered a new Accelerator pump and EGR unit that we're going to attempt to install over the weekend. I had the van out yesterday in this nice 60 degree weather and it ran very well, seems to be temperature conditional, which will make it hard to tell if we actually fix anything this weekend. We'll check the timing as well but the guy I bought it from insists that he just changed and adjusted the timing trying to troubleshoot the backfiring and stalling problem.

 

did you remove the egr yet to see what it looks like?...i just recently removed mine on my 88 318/5.2 and that thing was so clogged, i just took some gumout carb cleaner and put it back in with a new gasket and it doesnt stall anymore but it backfired a couple times when cold, you see im having similar problems with mine.

 

Ninja is correct I goofed. I recently found out that tbi started in late 88 or early 89 depending on engine size.

 

Am I correct that the 1989 B250 318 5.2 has a Throttle Body Injection system? I'm reading up on them online and found...

"Throttle body injection is much like a carburetor except that there’s no fuel bowl, float, needle valve, venturi, fuel jets, accelerator pump or choke. That’s because throttle body injection does not depend on engine vacuum or venturi vacuum for fuel metering. Fuel is sprayed directly into the intake manifold instead of being siphoned in by intake vacuum. "

If the the system doesn't have an accelerator pump what else might it be?