Help!! C15 Problem!!

Mmmmm I had similar but different problem in a Pete I was driving last month. But I saw what was happening, the key was switching off on me when I hit a bump. First I thought it was to much stuff on the key ring, but that did not help it. But I did have fun with it. I was working for a lady, so I told her her truck had a Ghost in it that turned the key off while I was going down the road.

 

It is in the ignition system. Check all your grounds, even the obvious ones.

The TPS would give you half, partial or full throttle, and cause "bucking" while driving as it looses its signal. I dont think it would shut the truck off like that. But it would be a definate drivability problem.

 

I would replace the ignition itself, the mechanism on the dashboard, i remember i had that problem on my 92 379, it would do the same thing. First check all the wiring going to and from it, you could have a nicked wire somewhere and that will cause it as well.

 

My truck was doing just what you said, it turned out to be the camshaft position sensor up on the left front of the engine near the top. The plug on the wiring harness had some corrosion on the pins. I found it by shaking and pulling the engine wiring while the truck was idling. When I shook that section of the harness, the engine died. I cleaned the pins on the plug up with some carburetor cleaner and a q-tip. That was back in Feburary and no problems since. Before I figured out what it was, I would be trucking along and the engine would just quit, the 9 times out of 10 just start right back up again. Good luck

 

Hi, I own 3 units with a C15 and they all had a share of a problem like that, in these 3 cases the common denominator was loose cables anywhere from batery terminals to cables attached to starter.
See as bad contacts interrupt the otherwise good connection to and from the batteries the computer ID's it as a malcfunction, and will try to shut the engine off, as it reconects again (a very short lapse between good and bad connection) the engine pc will not write any codes. I hope this helps you out, it took me a while to discover this , the dealers coud not reproduce nor FIX the problem (no codes in pc,ecm). As I observed them cheching this problem out ,I realized they never check the batteries .