TallTom

On the way to work this am, I was running around 48 mph when my check engine light came on and my tach dropped to zero. It was about 3/4 mile before I could pull off and by the time I got to where I could pull off the tach jumped back to about 13,000 and I was running around 50 mph. At that time it seems to have a burst of power and spooled up and ran fine.

It was about 28 outside could there have been some ice crystals on a connection ? This would be the second time it had shifted through the gears this morning. The first time there was no problems at all.

Plan on driving this truck to various Christmas dinners and don't want to have any problems with the family riding along.

TallTom

DodgeCowboy

I think and I could be wrong but if your 24valve guy you may be able to cycle the key on off on off on and be able to read the codes and go from there and post them up here so we can diagnose the situation and also there is codes and what they mean in the wiki sight.

TallTom

Sorry us early 24 valve guys don't have that option. I have been using the search on this site and and found it might be a ground problem. I will check out everything when the sun starts shinning today.


Tom

DodgeCowboy

I hate ground problems so many places too look maybe its just the main ground. I think you could run to auto zone or some place similar and have the codes read. The 60 dollar pocket scanner was the best investment I have made. Its came in super handy for a variety of cars I own or family members cars.

high country

cam position sensor or crank position sensor would be where I would start.

bent valves

The crankshaft position sensor is likely the cause of the problem you are seeing and will generate a P0336 code. The CPK provides engine speed and position reference to the ECM. The tach signal is derived from this sensor. If the CPK signal is lost while the engine is running, another engine speed signal derived from inside the VP44 will take over and allow engine operation (maybe in limp mode). Without the CPK signal the engine will not restart because of the loss of the crankshaft position reference for #1 cylinder.

My suggestion is to have the truck scanned for trouble codes. If it does not start just replace the CPK. I have read that some of the early ISB engines had a problem with the tone ring on the crankshaft coming loose and damaging the CPK. It’s a good idea to check the old sensor on removal for damage to the plastic. If it is damaged the tone ring will need to be reattached to the crank. I hope you find no damage.

redbeast

The same thing has happend to me. But i had just put in a new position sensor in so i knew it wasn't that. I also had been chasing a ground for a long time. What i did to fix my problem was get some alluminum foil ducting tape and wraped my ground from the alternator. And boom it was fixed. I still have some problems every once and awhile but it is never really bad. My trans just jumps back and forth every once and awhile.

Grider Pirate

If you can get a local disount auto parts place to read the codes for free, I'd start with that. If it turns out to be a crank position sensor (you've got both cam and crank sensors), get the part from Cummins and do it yourself. It's not challenging, and the dealers all want too much money for the job. There's a good write up in the 24 valve engine and drivetrain section.