spark plugs (different question)

bassdog · November 8, 2001

Here's the problem -

I changed my plugs yesterday. The plugs I took out were Might Power Core plugs (never heard of them before) and every single one was corroded, but clean. None of them were gapped correctly (anywhere from .040 to .047), the gap is suppose to be .035. The truck ran fine anyway...

I put in new AC Delco plugs and gapped them to .035. The truck now skips! I rechecked all the plug wires, the firing order is correct (I do one plug / wire at a time ) , and each plug wore is snuggly fit, each one "snapped" into place.

What can be wrong? Do I have a bad plug? Does the computer have to re-learn the correct gap and new plugs?

Why would it skip all of a sudden after a spark plug change? How do I go about getting the bad plug out without taking out all plugs and checking each one?

By the way - the truck is a 94 Chevy with 5.7.

Help

bassdog

raventai · November 8, 2001

hmm, one thing u may try , new plugs will glow very slightly at night if u are in a verry dark area (no street lights) this will only work on new plugs as old plugs the carbon will cover the ceramic killing its light transmition

thats all I have

what year is your ruck? this only works on older style plugs where tha ceramic is exposed not my new truck as it has a metal shroud arround the plug

bassdog · November 8, 2001

It's a 94.

The only thing I can think of is to remove each plug and check them out. It's a pain, but I suppose it's really the only way to do it right.

DOH!

bassdog

November 9, 2001

Hook up your timing light like normal. Then move the pickup lead from plug to plug. Maybe you have a bad wire. If you find one that doesn't make the light strobe, BINGO!

bassdog · November 9, 2001

Hmmmm, I'm not very mechanically inclined, nor do I own a timing light ;). But I did do the next best thing; I changed the plug wires, cap and rotor last night (all AC Delco parts). The bad news is that it didn't help!! The "skipping" seemed to have gotten worse :angry:

This leads me to believe that I DO infact have a bad plug somewhere. ???

bassdog

bassdog · November 14, 2001

Yeah!!! I found the problem...I had one bad plug w/ a hairline crack need the base of the plug. When I went to take it out it finally gave and cracked in half.

I decided to go with the AC Delco Rapidfire plugs after the fact. Everything runs smooth again

Thanks for all the help

bassdog