So I have this really intermittent problem with my 93 Dakota where you can jump in it start it and it turns over great runs up to about 2000K RPMs dips back down to idle and then stall out. Sometimes when it does this the motor may still run; however it pops and farts, kinda like one of those old kids toys with the plastic ***** in it that would pop as you pushed it around, yeah I am probably dating myself on that one! Simply turn the ignition off and try again and normally it starts perfectly on the second or third attempt.

Last night I think the problem might have progressed a little further as when I started it, it stalled out exactly how I first mentioned, so I cycle the key off and try to restart it and BOOOOOOOOOOOM I got a single huge backfire out of it and it stalled again, I waited a couple seconds and tried again and it started an ran perfectly. Even this morning on my way to work I jump in the truck start it up and it ran fine on the first try, and it has not thrown a CEL nor am I able to pull out any codes from the ECU all I get is "55" which is end of error codes.

The truck is a 1993 Dakota LE 3.9L Magnum, 4x4, 5spd manual tranny. It doesnt have any aftermarket engine mods currently, and has had the following parts currently replaced that I know of:

-ECU
-Ignition Wires
-Plugs
-Fuel Pump
-Coil

The previous owner was a family member and gave me the truck knowing there was an issue and even told me but I can never turn down a free vehicle, there has been a bunch of other work done to keep it in shape but these are the ones I know for a fact. I have read that a faulty MAP, IAC or TPS may replicate a similar issue; however when the truck starts fine it drives beyond great not a single issue.

I also read that someone was having an issue with pre and post cat 02 sensors, I am not 100% positive if I have a post cat 02 sensor or not (havent flipped through my Haynes book yet) but I can confirm that the guts of the cat have been removed its just a housing so could this cause it?

I have also read that the distributor gear bushing I believe it was, is pressed directly into the engine block that may need to be replaced, some write up I was reading was saying if you can wiggle the rotor back and forth ~3/8" then this bushing is probably shot and can be messing up the timing, but that would be a constant issue would it not?

The last thing I can think of to check is the 3 and 1 splice I believe it was called under or around the fuse panel, as it maybe corroded and causing the issue; however then again I would think that it being electrical it wouldnt be so intermittent, I am at work now and cant really check, but for some reason for how much I have read on this issue I really want to check here first.

 

Is your timing chain making any noises? Sounds like a timing issue, you could be right on on the distributor thingy though, and you should have a second O2 sensor, unless someone figured out how to trick your computer.
good luck, keep us posted.

 

Nope the timing chain isnt making any noise, there is a very tiny chatter coming from the lifters; however this is really common so I am not concerned about that. I will agree with you on the timing thing 100% as thats what I thought it was aswell, hopefully it will stop pissing down rain here and I can actually get a chance to start trying to diagnose some stuff. I am really hoping its not the distributor bushing inside the block thats pooched something tells me its not an easy fix.

 

I would be suspect of the IAC. A decent cleaning of the sensor may help as well, and is cost effective.

 

I work in automotive so its amazing how cheap things can be! However I am going to start with the obvious, I am really fearing this distributor bushing as its quiet apparent that it is a common issue and it does require a couple hundred dollars worth of tools to do properly

 

Just a follow up, I have been doing some digging today at work for this distributor bushing issue as I am going to say its worst case scenario, it does require special tools to install and remove the bushing OTC Tool makes both of them

Part Number 6292 is the Installer/Reamer
Part Number 6293 is the Remover

Summitracing.com lists both tools at about $100 a piece, I'm going to call OTC tomorrow and see what our cost is on them since we are a dealer. I find it funny I was told by a couple shadetree mechanics that these tools were factory only and the job was going to be in the thousands.

The bushing is not available aftermarket, which really sucks, luckily since I am the aftermarket parts guy I called up the local dealer and they quoted me $12.19 for the bushing. The Mopar part number for this bushing is 01737725.

They say its directly correlated to the Oil Pump Drive Gear wearing, see TSB 18-08-93 Rev. A

Hopefully the weather they are calling for on saturday wont be snow, and will allow me to easily work on trying to diagnose this problem, I will keep this therad updated as to what I fix/replace and the outcome if it was positive, negative or nil.