So I have a 1998 2500 V8 5.9L with 153,000Miles. On Monday I noticed the coil wire to the distributor was routed wrongly so I disconnected it and routed what looked correctly and hooked it back up to the coil and made sure I heard the snap back onto the coil. Then later that night and now consistenly when I come to a stop the RPM's dip and stall. It is after the truck warms up after about 5 mins. I can be backing into a parking spot or just coming to a stop and it will just stall.

It has new a new Idle Control Sensor back in June but through surfing through the forums looks like it could be the TPS? Or PCM?

Before I replace those is there something I could have done to the coil disconnecting it and hooking it back up with the battery still connected?

No engine light on, no way to read the codes right now. Spoke to a mechanic on the phone and he said it was cheaper to replace the TPS 1st before paying to diagnose.

Ideas?

Thanks

 

There is a link to the Factory Service Manual for 2001, but it should be the same. I would look there or use a Haynes or other reference, and check the TPS before buying a new one. It is a simple test with an ohm meter.

I would also check the IAC to see if that was the problem. PCM is not likely suspect.

 

Ditto on testing the TPS before you replace it. It's really easy.

To me, the big thing is that this started right after you moved the coil wire. I'd check to make sure you didn't accidently disconnect something in the process; I think the temp sensor (for the PCM) is located along that path. If it didn't get disconnected, it might have gotten broken; they get really brittle and crumbly after a few years. No temp input might have something to do with the stalling beginning after the truck is warmed up.

Can't see how you could have harmed anything by just disconnecting the coil wire, if nothing else got touched.

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"No engine light on, no way to read the codes right now".

On my '94 5.2 I can get the codes to flash out by turning the key on-off-on-off-on. Have you tried that? Not sure if that works for 98's; might be an OBD1 thing.

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"98+ Rams do not flash the codes, but on 94-97 Rams, the owner can read the codes this way:

• Turn the engine off, then turn the key ON, OFF, ON, OFF, ON without starting the engine".

Well I guess that answers that. At least I finally found the single advantage to owning an old sh**box.
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Lastly, I just finally resolved a long-time stalling problem, and it was the CKPS (crankshaft position sensor). I now know for a fact that they are not an all-or-nothing item, but can go slightly bad and cause misfiring, most noticeable at slow speeds. Given how vital they are, it wouldn't hurt to take it out and test it. I just checked the resistance between any two of the three pins on the connector. (Come to think of it, you don't even have to take it out to do that, although it is in a tricky place, and taking it out might end up being the easiest). My bad one showed infinite resistance on all the combinations of pins; a good one will show about 3.4 on the 20K ohm scale. Wouldn't hurt to rule it in or out, although it still would be quite a coincidence that it just happened to go bad after the coil wire re-routing. Can't see what that could have done to the CKPS, either. Good luck.

 

Thanks guys. So I checked the voltage going to the TPS from the PCM and it was 5.15 volts which is good. Next I checked the resistance of the TPS and it was consitent and smooth with the throttle position. On the 20K setting it was 0.73 and then 2.66 at full throttle. Watching those you tube videos the resistance jumps all over the place when these units are bad.

Now I took another look at the coil wire and noticed it was put on backwards by the previous owner. I corrected it and noticed that it was not pushed all the way down on the cap. It is now turned around and secure so fingers crossed this is the issue. I will report back in a few days.