First of all, let me say that this site is an awesome source of information... thanks.

I am a mechanic on gas engines, but I am trying to help a friend whose truck is running bad. On gas engines, TDC is 0 degrees. Is this the same for a '97 Dodge automatic? He claims that TDC is 12 degrees advanced.

He just replaced the injector pump on this thing, set it at TDC, and now it seems to be running rich with poor acceleration. Only knowing about gas engines, I would consider this a computer sensor problem affecting the injector pulse. Bear with me, I only know basic operation of diesel engines and not the specifics.

If anyone has any suggestions, it would be much appreciated. Thanks.

 

TDC is TDC gas or diesel, it's when the piston is at the top of it's stroke.

12 valve timing instructions here http://dodgeram.info/tsb/1994/18-10-94a.htm

 

The engine dataplate will show how many degrees are built into the pump. My 97 5 spd pump is indexed to 13.5 degrees. That is for pump building/rebuilding purposes- it is still measured from #1 TDC. Craig

 

16.5 degrees advance will be much more fun than 12 or 13.

Chris

 

http://piersdiesel.com/TechPTiming.htm