96 lumina sedan 3100 motor missing on accelaration

[dagan06]

Service engine soon light does NOT come on so no shop is able to tell me whats wrong. It only does this when the car is warm. But it does not do it all the time either. Has anyone had this problem before or does anyone have any suggestions? I put in new plugs and wires in december.

[maxwedge]

Recheck your wires, make sure the are on all the plugs properly for starters.

[Blue Bowtie]

I'd also suggest checking gaps, inspecting the coil packs for cracks or carbon tracks, and testing plug wire continuity. I just went through this on mine, discovering a failed (less than a year old) plug wire right at the plug boot/connector.

[jeffcoslacker]

Sometimes a cracked insulator on a plug can do that too...

Is it just little annoying misfires or actually cutting out/bucking/backfire etc?

I ask because since each coilpack fires two cylinders, a coilpack or ignition module misfire usually involves 2 holes misfiring together, which in a six cylinder is very pronounced as a third of the motor is cutting out...a single cylinder miss feels much softer by comparison...

I just had another idea...if you can get it in the dark, like in a garage, or outside at night, with the engine good and warm have someone torque it up in gear while you look under the hood...sometimes if it's plug wires exchanging spark or jumping to ground, coil leak, etc you can see it arcing as it misfires...

[dagan06]

plugs and wires are fine recently noticed a smell of gas this helps narrow it down i'm not formiliar with fuel injection any sugestions

[jeffcoslacker]

Disregarding something just because it was replaced recently is the first step in lots of tail chasing and head banging....

Like I always say, if I had a nickel for every customer that ever said "it can't be_______, because it was just replaced" and then ______ turned out to be the cause.....

[jeffcoslacker]

If an injector was leaking enough pressure that it couldn't open sporadically that would cause it, and it would be more noticeable under acceleration, but it would be making a heluva mess...I've seen lots of them leaking pretty good and the car ran fine...

[dagan06]

i've checked the plugs and wires 4 or 5 times now i keep hoping it would be that simple i smell gass but no injectors are leaking no fuel leaking at all

[cf1]

Originally Posted by dagan06

i've checked the plugs and wires 4 or 5 times now i keep hoping it would be that simple i smell gass but no injectors are leaking no fuel leaking at all

check the coolant temp sensor.. my pick up did the same thing untill i replaced it.. mechanic said temp sensor bad sends wrong reading to computer that controls the fuel..

[dagan06]

that might be it it had been running warmer than normal i changed the thermostat over the weekend but its my wifes car and i didn't think to ask her if it was still running warm

[cf1]

Originally Posted by dagan06

that might be it it had been running warmer than normal i changed the thermostat over the weekend but its my wifes car and i didn't think to ask her if it was still running warm

dagon, when you replace that sensor, make sure that the engine has cooled down.. then unhook the battery and reset the computer..

[richtazz]

A bad CTS will normally trip a CEL. What brand plugs and wires did you use? If you have an old inductive type timing light, you can hook it to each plug wire and check spark on each cylinder. Any that don't have a nice steady flash are what is causing your misfire. I would put my money, since there is no CEL, on a bad plug wire or cracked spark plug porcelain. The smell of gas is indicating a rich condition (unburned fuel due to the miss). A miss under acceleration combined with the smell of gas is almost always an ignition related issue (plugs, wires, module, crank sensor, coils).

[dagan06]

i have bosch plugs and wires the only parts store in my area is autozone so i don't have much to choose from but i've taken every plug out and checked every wire i'm not seeing any issues with the plugs or wires or coil packs could this be caused by and egr valve?