Hey everybody,
I finally got around to doing a compression check on my 94 pick up 3vze.

I did disconnect cold start injector plug and distributor plug and had throttle open. The numbers on the dry test were low, so i didn't even bother doing a wet test.
Re-installed plugs buttoned it back up and ran jumper just to check for codes and got a code 12. Read as many threads but i'm a little confused-----Open or short NE circuit or STA or ECM. I re-traced my steps and didn't see anything I left unpluged or broke off. I'm completely stumped why I got this code now.

Any help is always appreciated.

 

So I checked the timing this morning and noticed that the timing mark is irattic not alot but not staying on the mark. Pondering if magnets on distributor are weak. I also read something about possible ignitor. Just don't want to start throwing parts at it. Will do some more checking after work.

 

Checked wiring last night, couldn't find anything wrong. Starts and runs ok. Tried to clear code just in case, but will not clear. Maybe find a used dizzy and throw it at the truck and see if that helps. A little frustrated right now. Maybe just walk away from it right now and re-think diagnosis.

 

So I thought I'd post myself again. Had a code 12 and finally had some time tonight to trace some wiring and found 2 wires going to dizzy frayed enough to create short. Repaired wires just on the edge of wire loom cover exiting to dizzy connector. Re-set timing and she's all good again. Even with low compression it still runs pretty good. Ya just gotta keep looking till you find it. No parts toss, no $$$ spent, awesome!.