Heres my problem. The car has an intermittent miss/stumble/hesitation, I dont even know how to really describe it. Seems to do it all through the rpms and under almost all different driving conditions. Lessens when I go WOT, but I can still feel like the car is surging. It doesn't feel like any secondary ignition miss I've ever felt. The car is getting enough fuel and the opti is new, coil is about a year old. I've swapped plugs and wires twice trying to figure it out but to no avail. It wouldn't bother me if I was just gonna drive it, but I installed a N20 kit almost a year ago and I've yet to spray, ,long story. I really want to get this figured out because I want to finally hit the bottle, but I'm hesitant because this weird stumble may appear in the middle of the run and I don't want to cash out a motor. Guy I work with who is a GM world class tech, said it didn't feel like a seconday ignition miss, he thought I may have a valve that is sticking, but he was just throwing out some worst case scenarios. Anybody got any ideas?

 

Sounds like the same problem I have. Mine sputters and backfires occasionally too, i thought it was bad gas or water in the mixture. I'm going to rip into the fuel filter and check out the plugs tomorrow to see what is happening. Let me know some of the things you have tried in the past that didnt seem to help, they may help me out, in the meantime i hope we can get some replies

 

Heres everything I have done. New opti, 2 sets of plug wires, 2 sets of plugs, coil, fuel filter, 3 bottles of injector cleaner. I've tested all the injectors they are flowing and spraying fine. Checked my 02 sensors, and just about everything else that is related to spark or fuel. I have good fuel pressure, and seem to have spark. Only things I haven't checked is to see if I have a valve sticking or if I have one cylinder that is maybe getting blow by or something.

 

Have you done a compression/pressure check on all your cylinders yet?? How do your plugs look??

Brandon

 

Wires?I would say slap some new wires on and away you go........they are notorius for burning wires.

I had one laying on the header once burned it bad, wasn't firing at all. And it drove like you are saying---hardly anypower when at half throttle and at WOT you can feel there is a ton less TQ and HP.

Here is a question, Does it get worse when it gets to normal operating temp?

 

I'm on my second set of brand new wires. This DOES NOT feel like a secondary ignition miss, like a burned wire. I've burned many wires on this car and this feels completely different. Not to mention I've had the car up in the air, in the dark, sprayed wires with soapy water, no arching any where.

 

Might do that this week at work. I need to send you updated pics and mod list of my car for your site. My info is out dated .

 

I've seen posts like this many times,and I was wondering if you are using aftermarket stuff?,like coil,or different plugs,ect.Do you see any light show when it's real dark out when you pop the hood?Sometimes the spark will climb up a un ribbed or short plug,then ground itself on the heatshield.Hope this helps.(stuff I've read before).Please post when you get this fixed.Hope this helps.