Hi Guys!
I've got a '96 2WD with a 3.9 engine and approximately 130K miles that often dies while idling (at stop lights). It was running badly (stalling, missing, occasinally backfiring), so I took it to a dealership for a diagnostic. They said the timing chain was bad, so I had a local garage do the work. For about a week, it ran better, then today it started dying at stoplights. It wouldn't start right back up, but after a moment or two, it would. When I got back home, it seemed to be idling well, so I think it may be the IAC. Could it be the IAC (Idle Air Controller), the TPS (Throttle Position Sensor) or the CPS (Crankcase Position Sensor)? Please give me your best reccomendation, as each sensor runs about $50 and I'd rather not throw away money on parts I don't need.
Any help would be appreciated.

PenultimateMoparFan

P.S. - Just FYI, the engine is running in the normal heat range (per the temperature
gauge), I changed out the rotor when the problem began, it's been 6+ months since
I checked the plugs but I doubt that they are the problem & the oil was changed dur-
ing the timing chain replacement.

 

did you try checking codes? when you do figure it out if a sensor is needed get it from the dealer.......no autozone when it comes to sensors!

 

No, I haven't checked the codes because the "check engine light" isn't on. I doubt that the hand-held diagnostic meters will show anything. If the "check engine" light is on, it's usually a false positive for the oxygen sensors.

 

http://www.dakota-truck.net/CODES/codes.html

 

Does it start right up in the mornings? I had a similar problem with my old truck. It could be the EGR. its pretty simple fix to buy rather tham putting out $100 a piece for sensors

 

Not all codes trigger the CEL. Check anyways. I've had numerous codes without ever getting a CEL. There is a write up in the FAQ on how to check. No need for the hand held diagnostic meter.

 

Your plugs could be fouled, your AIT could be bad, MAP sensor could be bad, TPS could be bad, check those parts. That's where I would start.

 

I think I MAY have stumbled upon the answer for the stalling - I exchanged my fuel pump relay for another and, so far, it doesn't stall anymore. As for the poor running & backfiring, I presume that the dealer was right that the timing chain needed to be changed. I'll keep you up to date on developments.