I cannot figure this problem out. When the car is cold it runs ok, not perfect but ok. But when it warms up it starts missing and bucking when driving and if I stop and let it idle it seems to be only running on 6 cylinders and then it will hit on all 8 then 6 again. The only sensors that haven't been replaced yet are the IAT, IAC, MAF, and TPS. Everything else has been replaced, o2 sensors, MAP, Water temp sensors, oil sending unit, knock sensor, deleted EGR, AIR, and my tune was done by madz28

The only thing that I can figure out is that either my tune is messed up or its my opti, or my MAF But I really don't think its my opti since it runs decent before it gets warmed up. And my check engine light comes on sometimes, but then turns back off and thats usually when its idling and missing. I was going to order an opti and a MAF, but I really want to figure this problem out rather than just keep throwing parts at it to try to fix it.

Any suggestions? My car has 120K on it it it matters.

 

My car did that and it was opti but ive only had this car 2 weeks so dont rely on just me.

 

Replaced plugs/wires yet? When my opti went, it had the same symptoms as yours -- it would run decent, but wouldn't start running like complete *** until it warmed up.

 

I would check plug wires... sounds like one is hitting either the belt or is hitting something hot... I have had the plug wires short out on the header before and it does that.

 

I would get the car scanned first, that could very well lead you to the problem.

 

Scan is only turning up that the MAP is reading high, but I have seen that thats caused by my cam???

Plugs and wires are brand new like everything else on this car. I went from a completely stock car to the setup I have now all at once and its really seeming to come back and bite me in the *** over and over.

Plug wires aren't burnt and are plugged in all of the way. I have accel fire sleeves over my wires so they don't get burnt. Plugs are ok, but not great but they only have about 20 miles on them but my car is running so rich it keeps fouling them. But I have 2 sets of TR55s but I don't know what to gap them at with my setup, 11.1:1 compression + shaved heads and decked block??

I talked to a friend of mine that knows these cars and hes going to put his old dyno tune in my car since I bought all of his old parts and we are going to see how that works out even though his motor is a 396 it might be better, but he can modify the program to fit my car. So I have to borrow a trailer since mine is loaded down with junk and take it to his place to try to get it sorted out. So thats the plan as of right now before I spend money on more parts that I may not need.

But thanks for all of the replies, when and if I find something out I'll let you guys know