I just changed my spark plugs 22C's to 12C's (have chip - had slight ping at 40mph).
After I changed the plugs the problem started.... Idles fine, it does have slight slight slight miss.
But when I put it in Drive and hold the brake (like at a red light) it will miss very noticably every 6-8secs.
Thing is I thought that maybe the plugs where damaged??? So I swapped the 22C's back in and it does it with them in it now too.
Well I think I found my problem. I did replace a few pieces of vacuum line, but I don't really think thats what the problem was.
Was working on it tonight, and had someone else throw it in drive while I watched; at least 4 of the plug boots where arcing!!! It wouldn't do it at idle, but as soon as it was in drive or reverse, BAM I could see the arcing plain as day.
I think I'm going to try some of the MSD wires. I'll let you know for sure tomarrow if that was the ONLY problem.
makes sense....a denser aircharge, like when in gear, will increase the resistance within the plug gap, so the spark looks for the path of least resistance to ground....but the plugs would have to be severly over-gapped for this.....are the plugs gapped correctly?....... if so, then sounds like the plug wires are to blame