I really dont think its a spark plug or wire because the miss is bad.. My friend Who felt it out said it feels like the old school cars when u dump to much fuel into the Carb and it.

I Noticed that my WOT threshold is at 60% so i guess thats when the computer goes into fuel/power enrichment. So it doesnt do the miss at all under normal driving... keeping it under 1/2 throttle it drives perfect. WHen i get it around that 60% throttle is when the car feels like it hits that brick wall for just a 1/2 second. Its like u just tapped the brakes really fast.

I think it'd have to do with tuning since a tuner was messing with my fuel when trying to figure out a loss of power problem (spun bearing didnt know it at the time).. So i dont know if he ever changed it back..

It feels like a timing or a fuel problem... Ive felt misses from plugs and wires and its harsher than that and if it were the plugs/wires or opti it should do it all the time when ever where ever and especially after the car is warmed up. Only does it over 50% throttle.. Basically everything on the engine or in the engine is brand new or has under 20k miles on it. I also used free scan to check what teh computer is doing but i really dont know much about tuning to understand all of it.
Any help would be much appreciated.

 

Sounds like the opti to me, but then again, it always does.

 

Mine does the same, I think its the opti too.

 

my guneia pig died , i think my opti did it

I dont know why yours would do that. I know my wifes 1984 firebird did the same thing but it turned out to be the fuel filter was 20 years old (yes its our beater , and no I never changed it). Dont know why it would do that on fuelie car.

 

Does it do it all the time or just when the engine is hot? Mine used to do it but only when the engine has been hot for a while. Took me three weeks to finally fix it and I should have just done this to begin with. Trust me, just do this mod. It's easy, and best of all, it's free. It can't hurt, and it fixed my problem....

ICM Cooling MOD

 

The Opti has about 800 miles on it. Replaced it and the vacuum harness and the opti electrical harness.. I dont think its the opti..

Its not heat related.. Does it cold or hot... Only over 50-60% throttle.. Never below it.

Fuel filter was changed about 15 thousand miles ago. Fuel pump has never been changed though.. That and the rear end are the only mechanical pieces on the car that are not new or basically new.

 

Maybe just try a new ICM. It could just be damaged due to the heat. Can't be that much money, it's only basicly a switch.

 

could be the ICM but i doubt it since that too has about 800 miles on it too...

Really when i say everything is new.. everything is new.. I can count on 1 hand the things that havent been replaced.

These new parts could still be the issue but the ICM usually gives u problems when it is exposed to to much heat... Car also has 180 fan settings so it never heats up to 205 or so like when it was stock.. Never goes about 180 really.

 

When you put the new ICM on did you put that heat sink grease behind it? With 800 miles on it, it prolly isn't the ICM as long as you have the grease on it. Without the grease, I would say that's probably your problem. If you have the grease, then I'm out of ideas for now. Sorry bud. Good luck.

 

o2's...

 

when mine stumbled at half throttle it was a plug wire

 

If it came with a grease packet from the dealer i did but i dont remember..??

"speed76demon when mine stumbled at half throttle it was a plug wire"
Could u go into more detail on this..


O2's are fine.. had Ion look at em on a free scan..