I've got a 98 Chevy 2500k that I think might have jumped time. It won't start, turns over fast then seems to almost lock up, fast then lock up, sometimes coughs and might even backfire. I know to use the #1 piston and turn it to top dead center then look at the timing marks but how far out is normal and how far off TDC is not. Any other way to determine if I have a timing chain problem before I tear it apart. That's a lot of work if I miss diagnose it. Thanks.

 

#1 piston TDC on compression stroke and rotor button must be pointing at the #1 spark plug hole/piston.

 

davbell22602 - Thanks for the return. My problem turned out to be a stripped distributor gear. I changed the gear, did my best to look at the cam gears (had to take a picture because I couldn't get my eye over the hole) and it started right up. I had TDC and #1 spark plug lined up. It runs good but the check engine light keeps coming on. The fault code says camshaft to crankshaft position and the number is P1345. I understand that the truck has to be timed at the dealership or somewhere with the technology to set it. I tried a couple times unhooking the battery and slightly changing the distributor setting then clearing the code but I never got the check engine light to stay out. It runs great but I'm worried the distributor might be moving and tear out this distributor gear. Your thoughts?

 

Anything 96 and newer has to be timed with the diagnostic machine.

 

Thanks for the reply. Is P1345 the code it will send if the timing is out?

 

Give it a few days gopedal, it may go out. These comps can adjust. But if it doesn't go out, then a shop with a ODBII scan tool can adjust the base timing.