Stumbling while accelerating

[kylec]

Background
1998 Firebird 3.8 auto, 67,000k
About 3000 miles ago (September) the car started missing when under load. The plugs and wires were only 2 months old so I started replacing coils. After replacing 2 of 3 coils the problem was corrected.

This week the problem returned. Since 2 coils were new I replaced the 3 coil which didn't help.

Last night I had my daughter hold the brake and keep it loaded and missing while I looked around for any arcing from plug wires and didn't see any.

I guess my next move will be changing the ICM to the tune of $125 unless someone knows of anything else I should try first.

The fuel filter was changed with the plugs and wires.

Any suggestions?

[Crazed98Camaro]

Re: Stumbling while accelerating

It throwing a SES code I'm guessing.
Go to Advanced Auto and get it scanned for free.

Tell us what they give you.

[Gatt9]

Re: Stumbling while accelerating

Yeah, but sounds like a problem I have had alot. on the '98's the wires on the passenger side are too close to the manifold, they heat and melt and crack frequently. The wire can even look ok, not arcing or anything, and still be bad.

I'm going to guess you're gonna get "Cylinder 5 misfire" as your SES, grab a set of wires while you're there if you do. That'll probably be the problem.

In fact, it's exactly why I paid for the coating on my headers. If it saves me just one set of wires a year it pays for itself.

[kylec]

Re: Stumbling while accelerating

I left that important detail out of the original post. The code was a misfire on cylinder 6 both back in September and this time.

[HeadyFirebird'00]

Re: Stumbling while accelerating

injector maybe

[bigbrian442]

Re: Stumbling while accelerating

Swap coils between cylinders and see if the miss moves with the coil.