Thread: Missfire under boost.

SO i got berta back today, the coolant leak was fixed but now whenever it goes into boost it starts missing.
Heads were checked and re done during the last set of repairs so im guessing its ignition related. Only thing i can think is when the coolant sprayed everywhere the ignition coils got soaked, or i have a cracked spark plug.

double check the wires are on right. if they are, you should be getting a misfire code. check that plug.

No code yet it runs just fine when its not in boost so the wires are fine

double check em any ways. car can run pretty damn good with two wires crossed up.

Wires are in place, on my way to class, on the interstate in rush hour traffic, it pretty much failed, any more than 5% throttle and misfire.

Did set a code, Cyl 1 misfire. Not sure if its the plug wire or coil

you know what to do now. at least the code popped and gave you a starting place.

Hopefully chip didnt pay you a visit.

The plug did not fix it, however the plug did not look broken so i dont think its chip. Especially since i had it apart a little while ago and it was clean only had 60 miles put on it since then.

swap the plug wire with the one next to it, if its still missing on the same cylinder, swap a coil round.

Odd, its much better after its been sitting, i can even go into light boost.

one of the benefits of my dad working at a "bad credit" Used car place, Lots and lots of early 2000s GM parts. He has a bunch of coils I can have.

No fix, it took more boost to make it miss, but i think thats because she was ice cold. Replaced the coil and the wire. Only thing left is the ignition module/platform

you sure you didnt pinch the harness at the coil bracket? its grounded and all?

I can double check, but its only on cylinder one, would a bad ground cause that?

the icm harness ground. its a eye let on a black wire, gets bolted down to the side of the coil bracket.


iirc you said you tore the engine down. just thinking of odd ball crap that can happen during re installation.

Yeah my dad put it back together so im honestly not sure. Hes a master tech and works on 3800 all day so i doubt it, but im going to check regardless

It was crunch time with the move so i let him take the lead

those are two things that can happen to the best of us really if your not watching out. seen it happen here more then once. caught myself starting to pinching my own. its a tight area.

No go, the harness is freely moving, and the ground loop is between a bolt and the bracket firmly tightened

I would replace the companion cylinder plug and wire as well.

Jeff

Is the plug seated correctly ? Gapped correctly ?