[Cybrjaz]

OK - I guess after reading 5 years worth of essentially the same issue - I'm going to add my own dilemma.

My Wife has a 99 Durango 5.9L 4X4 with 175,000 miles. About a year or so ago it started jerking around when you tried to keep the vehicle running at a steady 50 MPH - At times it would almost seem like the motor was going to rip itself out. Accelerate to over 60 MPH and no problems - let off the gas and no problems. We took it to several shops AND dealerships and NO ONE could give us a straight answer (ranged from everything from transmission to the vehicle computer). Anyway - Wife said forget about it she would deal with it until something else happens.

Flash forward to about three weeks ago. She calls me up and says her check engine light is on and the truck sounds like its missing (yes - I am blessed with one of those rare Wives who ACTUALLY KNOWS something about vehicles). No problem - I get home - hook up my handheld scanner and it reads a misfire in cylinder #7. So, I figure its as good a time as any to go ahead and do a tune-up. New plugs, new wires, new cap & rotor. Replaced everything and I'm feeling pretty good . . . UNTIL I start it up after the tune-up - It sounding 100 times worse than BEFORE I tuned it up. I hook up the handheld and now I'm getting multiple misfires and a "P1391 (M) Intermittent Loss Of CMP Or CKP Loss of the cam position sensor or crank position sensor has occurred" error code.

I recheck everything and use the scanner to reset all of the trouble codes on the truck. Next thing you know - everything is running fine and there are no error codes registered.

Next day my Wife drives the truck and calls me later in the day and says it stalled at a stop sign but fired right back up and is driving fine. OK - maybe a fluke but then it happens again the next day and the Check Engine light comes on. So, I hookup the handheld again and this time I only read the 1391 error code.

So I do a little checking and figure the easiest place to start is the Camshaft position sensor and so I get a new one and hook it up. NO CHANGE IN CONDITION. So I then (agonizingly) change the Crankshaft position sensor (again - what a complete pain in the ass to change that thing) and start it up - clear the codes - recheck and all is well. I walk into the house and tell my Wife all is done and she goes down to the truck and starts it up and it sounds horrible. By this time the truck is revving erratically and stalling out in park.

So now I'm searching the forums and DUH!!! - I forgot to disconnect the negative thereby resetting the vehicle computer. So next day - do out and disconnect the battery . . . for an HOUR!!. Hook it back up - start it up - and ALL IS WELL!! I now have to buy new clips for the inner fender well (which you have to take off along with the passenger side tire to change the Crankshaft position sensor in all of about 3 inches of space between the back of the block and the firewall - again - real pain in the ass) so I drive to the parts store (about 5 miles away) and it stalls right in the parking lot.

By now - I'm pretty ticked off (except for the fact that up until that point the two fixes cured the initial problem at 50 MPH) - I go in and buy the clips and limp the vehicle back to the house where it sits in the driveway right now.

I've gone through multiple forums and I'm now at my wits end. I have all of the same symptoms as everyone else WITH THE EXCEPTION of the NO BUS code . . . I DO NOT have that issue. So I'm left with changing out the vehicle computer . . . I Think?!

3 Questions:

1) Lots of talk about PCM and ECU are these the SAME thing?

2) It has been suggested that if you replace the ECU (nothing about the PCM - if they are the same then that is strange) then you should also replace the IAC - is this true or am I just giving away more money?

3) Does the fact that I am NOT getting the "No Bus" signal indicate that I have a different problem?

Thank you for your time and patience and ANY advice will be extremely appreciated. I can be contacted at [email protected]

Thanks,
Rick