Join Date: Jun 2009
Location: Saipan (!)
Mad Max is offline
Re: 2.8 engine miss enigma
I recently sold my 99 S10, and the deal breaker (almost) was a slight miss. It didn't happen all of the time, but when it did, the truck was useless. I sort of knew what it was though...
Turned out to be 1 bad plug wire. The truck would idle smoothly and skip once in a while. I looked at the wires, they looked to be in good condition.
So, I waited until it was dark out, and ran the engine. Sure enough, I saw a spark jump on #2 cylinder - only ONE time!!. It was not audible from outside with the hood closed.
I replaced the wires and the problem went away. #2 plug wire had a tiny cut in it at the spark plug boot.
Now this going over a bump thing....
Almost all of the connections on this truck are weatherpack connectors, so they don't come loose. They also don't corrode easily.
I'm not suspicious of your ignition switch, usually the dash lights will flash (charge light or brake warning light) if it's turning off and on. It is a possibility though.
Has this ever been apart? Like engine out of truck?
Also, check you ECU connection - the big plug. If anyone has ever messed with that, it is possible that the clip holding the plug tight may have been installed incorrectly. (unlikely, but grabbing a straw)
Oh, and for the hell of it - check the connectors on your TBI injectors. If they are faulty, this could cause this problem too.
1)'82 S10, 383, 700R4, Shorty
2) '85 S10, 3.4, 700R4 4x4 stretch cab (Redneck)
3) '90 S10 2.5, 5 speed shorty
4) '91 S10, Built 3.4, 5 speed shorty (Voodoo)
5) '92 S10, 2.5, 5 speed shorty, (Barbie)
6) '92 S10, 2.5 5 speed, Shorty
7) 1979 LUV, Buick 3.8 V6, TH 350 Shorty.