Hello to all. I just recently joined and I am posting my first question. My 1992 Dakota, 3.9L 2WD has developed a engine misfire. The truck has 221,230 miles and this is the first problem encountered with said truck.
During idle, off idle, or cruise the engine will stumble, feels like a dead cylinder and check engine light illuminates. The condition is erratic, will run okay for a couple of days and then the problem returns. I scanned the engine computer numerous occasions at O'Reilleys and consistently read code 27, left bank misfire, input signal low or not detected, cylinder one misfire.

At this point I have replaced the fuel filter, ignition coil, plugs, plug wires, rotor, distributor cap, crankshaft position sensor, thermal temp switch and removed and cleaned the idle air control valve, and throttle position sensor indicator.
I feel the ignition system is the culprit. In the driveway when the problem occurs, I detect the smell of an excessively fat, rich mixture which would suggest that the injectors are delivering fuel but not receiving spark.
I am at wits end. Should I replace the distributor next. I opened up the Schrader valve on the fuel rail near the intake manifold and gas shot towards the firewall so I think fuel pressure is okay.
I realize this is long winded, please help. Thanks

 

Bump. Anyone? Help? Thanks

 

Okay. Now I replaced the hall effect pickup assembly in the distributor, still getting the random engine roughness followed by the CEL and then code 27. I opened the wire bundle under the relay box and found dirt and moisture in the wire loom . I repaired some of the splices and it ran okay for about one day and now the condition has returned. Maybe I am on the right path.

 

RAN INTO THIS MYSELF. WAS TOLD TO REPLACE ECM. SO I DID THAT WITH THE PERFORMANCE ONE FROM MOPAR. WELL THAT WORKED FOR ABOUT A MINUTE AND DID THE SAME THING. FOUND INJ#3 WAS FIRING AS A STRAIGHT ON SHOT WITH NO PULSATION. SO IN OTHER WORDS COMPUTER WAS BAD AGAIN...NO WARRANTY ON PERFORMANCE PARTS...SO WHAT I DID WAS TAP OFF OF CYL#1 INJ BECAUSE THEY ARE A BATCH FIRE. SO FAR RUNS AWESOME...I DO LIKE THE PERFORMANCE COMPUTER....BUT WHY THE INJECTOR KEEPS DOING THIS I HAVE NO CLUE...AND I DID CHECK RIGHT OFF OF THE COMPUTER ON THE INJECTOR PULSE SO I KNOW ITS INTERNAL. HOPE THIS HELPS SOME

 

Thanks 92Dak. I replaced the TPS and the ECM temperature switch. As of this writing the problem has not reoccurred.
I also spent considerable time opening up the wire bundle under the relay panel in the engine compartment looking for corroded splices.
I am not one for liquid remedies, but none the less I tried a can of Seafoam in the gas tank.
I honestly feel the engine is running better than before the problem occured.
Items replaced in my trouble shooting, parts replacement mission. Plugs, plug wires, rotor, dist. cap, dist pickup assembly, ignition coil, crankshaft position indicator, idle air control valve, throttle position sensor, intake air temp switch, fuel filter and ecm coolant temp switch.
Other than normal maintenance items, this is the most I have spent on this truck in the last five years. I feel it was money well spent. I will keep you posted.

 

Is your fix (tapping into another cyl in the batch) still working? The dealership told me today that my Power Control Module has a bad connection for one of the cyls, and is not spraying fuel at all for that cyl. The injector is ok (they put it on another cyl and it worked fine). They wanted $850 to put in a new PCM and clean the fuel delivery system, but if I can tap into another cyl, that would save me a heck of a lot of money. Has anyone else ever tried this remedy?

 

$850 for a new PCM? I purchased a rebuilt unit from O'Reilleys for $168.00 including tax. The unit also comes with a lifetime warranty. I would suggest you shop around at your local parts stores and replace the unit yourself. It takes less than three minutes to swap out the ECM.

RAN INTO THIS MYSELF. WAS TOLD TO REPLACE ECM. SO I DID THAT WITH THE
Is your fix (tapping into another cyl in the batch) still working? The dealership told me today that my Power Control Module has a bad connection for one of the cyls, and is not spraying fuel at all for that cyl. The injector is ok (they put it on another cyl and it worked fine). They wanted $850 to put in a new PCM and clean the fuel delivery system, but if I can tap into another cyl, that would save me a heck of a lot of money. Has anyone else ever tried this remedy?
[/quote]

 

Are PCM and ECM the same thing?

 

Probably. Not sure of the exact vernacular when referring to your specific Dakota. I have a 1992 Dakota and have used bothexamples to describe the computer.
Again check out a rebuilt unit. Mine was a unit from remanufacturer company called "Cardone".

 

Ya there the same PCM Power Control Module, ECMEngine Control Module. I had this happen to me too on #2. I replaced the pcm once, then I bought mopar high per.comp. then that did it too. So I bought another high perfor. comp. from another company and that worked perfectly. But before I got it working right I replaced the injector and set up jumper wires and everything nothing worked exept for jumping #2 to #4 and that worked. so for you like he said jumping #1 to #3 would work.