i have a 94 S-10 with the 4.3 vortec. it was a barnyard find, it was sitting in an old guys grove for a few years as he thought the fuel pump went out. i bought her and drug it home and later that day found that the fuel pump was fine, but it didn't have any spark. not wanting to deal with figuring out what part didn't work i just replaced the entire distributor. ran perfect for a few days, but then it started running like junk. i found the EGR was loose and i had a vacuum leak, but when i fixed those it still idled like hell. spent a few hours messin with it and i couldn't figure it out. i pulled the distributor off multiple times and one day it just wouldnt start. i finally got it to run like crap and said **** on it. a day later it runs almost perfect. im baffled so i asked another mechanic and he says it has a computer thing that adjusts the timing after running awhile. i need to know how i would completely reset the timing. not sure if i unhook and rehook something or what. plz help!!

 

If you pull back the passenger side carpet from the dash area and pull down you'll find some wiring the thick loom is your ECU and there should be another single wire there with a clip, that is what you disconnect to check your timing with a timing light.

 

okay cool thnx i will check that out tonight. i bought a set of pulstar plugs so i planned on fixing the timing when i put the new plugs in.