I have a 1994 Dakota 3.9. Here is a little history on the truck. It has 225000 miles. Sixmonths ago the timing chain broke. I gave the engine a valve job replaced the push rods. Cleaned the intake, new timing set. yada yada. The machine was back on the road and almost as good as 1994. I got a bunch of fire wood and ran errands with it until January. Then it all began. Overtime the truck would start andit would Backfire.Just run like crap for a while. Then I'd turn the key off start it back up and presto. It ran fine. So being the procrastinator I am I ran it like this till last week. It just wouldn't clear up. So I gave it a full tune up. Cap, rotor, wires, plugs. Nothing, so I replaced Map AIC and inspected the distributor for play. While inspecting the distributor I found that when I reinstalled the EGR, the gasket wasn't seated properly. I bought a new gasket and replaced it. VROOM the old bugger started right up. Took it for a spin around the block. Shut it off in the driveway and now it starts and just rumbles right off. I'm stuck. I need some more ideas bounced of me. With all these problems I’ve never even seen the check engine light.

 

plugged catalic converter? feel any exaust out of the tailpipe? by any chance does the 94 have the timing chain tensoner on it? if not, ive learned the hard way, autozone has it, i'd get it. you didnt get to look at rod and main bearings either, right?

 

Just went out and tried it again befor I go to bed. It started right up. Seems like when it is cald she runs like a beut. I can rev the crap out of it. Took it for a rige again runs great untill I shut if off. It seems like I have to wait for it to cool off again. Maybe I'll take the egr off and clean it. I don't know. I need to goto bed But I'll check back in the morning.comments please!!!

 

No on the chain tensoner

 

well as long as you didnt have slop on the chain, should be fine, my chain went out because of cataclic convertor, or atleast i think it did, when it's plugged it creates a back pressure in your exhast system. i guess a good way is to check if it is blowing gas out of the fuel intake, it should be sucking in the gas....if your out ridding it at night, park it, look underneath, see something glowing red hot? if you do, means it probably plugged and i wouldnt drive it until i got it fixed. I was driving down the road one day, noticed a car that appeared to have lights underneath, which turned out to be a plugged up catalic convertor. the teenagers didnt know that was the problem, just knew that it didnt want to start right and ran rougher than normal...that was the only time that ive ever seen something that hot.. what does the temp gauge read? could it be a bad temp sensor?

 

It seems like the timing is off when the truck is at operating temp. If you start it up and never shut it down it will backfire a little bit when you shift but it won't stall. Once you shut it off it will not run again. Of coarse till it cools down. WhenIattempt to start it after it is warm. The spark seems to jump around radically. I thought I could here the spark jumping around in the cap. When I remove the cap it has white residue all over the inside. Where the spark is suppose to hit the little tabs. Hmmm

It also sounds like the AIC valve takes a little longer to close when I restart the truck.

I forgot to mention that I've also replace the mat sensor the coolant temp sensor. I replace the coil too. It didn't look cracked but it was worth a try.

 

when you replaced the cap, did you make sure 1 is at 1? there should be an arrow on one, and a one marking on the cap, line that up....

 

I wish it was that easy hitandrun. The cap only fits on one way. I was wondering if the o2 sensor could also mess it up. Or is it the type of sensor that either works or it doesn't. I'm not sure what to replace next..........I don't have too many takers on this mess. Like I said it will run fine if I start it up when I get home from work. Once it has warmed up, and has been shut down. It will not start back up. Should I replace the crank sensor. How can I check to see if it works properly??

 

Are there any codes stored in the computer? Just because the check engine doesn't come on won't necessarily mean there won't be codes stored, thurn the key fore and aft five times with out starting the truck, the codes will blink 1 blink pause 2 blinks is 12, then match the code with the issue. The haynes manual lists them or you can share them with us and we can "decode" you.

 

DUDE!!! Good call. I didn't check the codes. I've been working on so many obd2 cars I just figured the check engine light would have came on. Well I'm happy to say you were right. The codes are 12-24-31-55. I thing 24 is TPS. Not sure about 31. Should I just replase tps and reset pcm? See what happen after that..........thanks again Cody