QuestionQUESTION: Van runs rough or quits after approx. 15-30 min. of driving after morning start up. After stalling, I let it rest for 5-10 min. and it will then art up and run good the rest of the day. A dealer and a local mechanic have yet to diagnose the problem, even when diagnosed by computer. So far, they have replaced: coil, PU at bottom of distributor, removed and cleaned gas tank, replaced pump and filter, replaced catylitic converter, and replaced loose timing chain. Van STILL has same problem. Only on a couple of occasions, it behaved an entire day without acting up. Do you have any suggestions? Thank you.
ANSWER: Hi Rod,
Which engine is in the van (# of cylinders, and how many L)?
Without a fault code the diagnosis is difficult. One of more common components to cause problems that don't set codes is the EGR valve so check to be sure that the stem of that valve moves freely and that the internal spring-action closes it to a dead stop. If not, then lubricate the stem where it enters the valve body with WD-40.
It could also be the other engine rotational sensor if there is one, which I will know when you tell me about the engine. Those often begin to fail just as you describe (failing after warming up, then recovering after cool down). So keep watching for fault codes using the igntion key for at some point the problem will be noted and logged into the PCM memory.
Please 'rate' my answer (see the PS below).
Thanks,
Roland
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QUESTION: Hi Roland, the van is a V6 - 5.9 L
One other thing, it doesn't need to cool down completely to start up and run good for the rest of the day, warmed up.
I don't have the fault code at this time, I will ask my mechanic. I guess I'll need to get back to you with that.
Thanks.
Rod
ANSWER: Hi Rod,
As I don't have manuals for the '90's vans I am unable to give you more details. None of the manuals I have is for a V-6 with 5.9L. So all I can suggest is that you keep trying to get faults codes. By '97 in the car lines (and probably the vans) you could get a code readout with your ignition switch:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the 'check engine" light, which remains 'on', to see it begine to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat the process to be sure of an accurate set of flash counts. Then tell me the counts in order of appearance and we'll go from there.
Thanks for the follow-up rating and nomination.
Roland
PS: Just for clarication, might not this be a V-8 gas engine, or a straight 6 diesel engine as to have a displacement so large as 5.9 I would believe that the gas would have 8 cylinders or that it is a diesel straight 6?
---------- FOLLOW-UP ----------
QUESTION: Roland, I apologize for my typo. My van IS a V6 3.9L.
I tried what you suggested with the ignition key but check-engine light never came on.
I also called my mechanic today and he says the only fault code reading he got was for O2 sensors.
Several years ago, the engine light came on and stayed mostly on but the van kept running fine. The current problem I have started 4 months ago and when my mechanic hooked up a computer to the van, it showed that O2 sensors were bad. He changed the catalytic converter and the check engine light doesn't come on anymore.
I still need to check the EGR valve and I will do after work today. Thank you again for your valuable suggestions. I still hope to solve this mystery as I sure don't look forward to buying a new vehicle.
Rod
AnswerHi Rod,
I notice that the mechanic said a fault code came out for the oxygen sensors. The code should specify which sensor(s) is bad and thus if that hasn't been changed it may be worthwhile doing that in the hope it would alleviate or solve the problem, if that wasn't done (I didn't see that listed in your original question as an item than had been replaced).
Because I don't have a manual for the 90's ram vans I can't know for sure about the egr being there or not, but look for it and if present do check the 'action' of the valve stem and lubricate it where it enters the body of the valve.
The stalling when warmed up certainly is associated often with the rotational position sensors. and there may be a crankshaft sensor which is becoming flaky when heated up. You said that the sensor on the distributor (which would be the cam sensor) was replaced. It may be that a code will soon appear that points to the crank sensor signal being bad (that would be a code 11 or a code 0320 depending upon which type of reader was used to look for it). So other that checking for fault codes (which you can get a readout for free at nationwide autoparts stores such as Autozone) until something appears, and checking out the egr valve, I am not able to suggest further what to do.
Thanks for the prior rating and nomination. You can do both those again in response to this answer if you think that I disserve that recognition.
Roland
