ok guys, im ususally pretty good at this stuff but now im completely dumbfounded. 1997 Trans Am M6. stock. 144xxx. started running rough and throwing random cylinder missfire codes. but its odd how it runs. if your just drivinvg around normal, the thing does fine and no ses light. if you put it under a load, she starts to break up in upper rpms. and after you have put it under a load like that, it runs horribly even at a steady speed for awhile. so, i began replacing things. it now has: new accell optispark, new accell coil, new plugs, new wires, new passenger O2 sensor. when it runs bad it pours black smoke out the exhaust which leads me to believe its definatly gettin fuel. when i changed plugs and wires, all the plugs on drivers head looked as they should. however all on passenger side were soot black as an ace of spades. thats what led me to beleive passenger O2. anyways, none of these things helped AT ALL!!!! it also is running at a much lower rpm esp. with the a/c on. my car has always idled at 1000rpm since i bought it. now, 800 no a/c and 500 with a/c on. i brought it to the gm dealership b/c i am sick of it. i was told they had a corvette and gm performance tech who's sole job was sports cars. 3 days later they told me to come pick it up because the tech was pulling his hair out trying to figure it out. so, today im gonna change the fuel filter just cuz and maybe throw a match to the whole damned thing

please help me out if you can, kenny

 

anybody?

 

you may need new plug wires...that happened to me..

 

i had thought so, but i have changed them and no difference. thanks alot though

 

Have you looked at the injectors? How bad were the passenger side plugs? you said they were black, were they oily? Does the car eat oil? Have you ever messed with the computer? Just guessing.

 

my first thought would be fuel pump, filter, or regulator

 

i replaced the fuel filter today, no difference. the plugs were definately sooty black, but no oil and doesnt burn any either. i have never messed with computer, but i have only had it a little over two years and 30,xxxmiles. i did put some injector cleaner in it but it seems to be more than a coinidence that only the passenger side plugs were like that. i hate electronics!!!! who wants it?!?!?!

 

i have had some problems like these. My lean codes went away after I changed the fuel injectors out.

 

I'm sorry bro, but I just dont know what else it could be. To me, it sounds fuel related, cause of the blackening of the plugs. And it has to be at the engine cause if it was fuel pump or filter it should effect all cylinders, not just one bank. And the aparent rich condition would rule out the filter and pump.


Is the comp throwing codes? I dont remember if you mentioned anything about that in your original post. Maybe you should look at the cat on the side that has been acting up. Maybe it is coming apart, and is partialy blocked, and therefore isnt capable of flowing the exhaust gasses. If the valves are unable to replentish the oxygen in the cylinders, It would be unable to burn the injected fuel.

Good luck bro I hope you get it figured out.

 

the only codes it throws are random cylinder missfire codes. and the ses light is intermittent. comes on when it is under load at high rpm and flashes or when on the interstate for a while. but the cat may be the problem. gonna have to check into it. makes sense to me. thanks alot everyone so far for helping

 

Keep us posted on your situation.

 

Yeah one of the cats is a good idea.

 

Mine is doing something like that right now only it runs like crap from startup. I've isolated a wiring issue. Do you have headers? On one of my early problems a few years back, the wiring harness that descends down the passenger fenderwell had been torched by my SLP headers. My passengerside O2 wires were burnt up but it was at such a location, I couldn't see no matter how I tried. Until one day I pulled off the Y pipe and I could see. Boy did I cuss. I'd been driving around in Open loop (via LT1 Edit) for 3 months because of that. The infrequent 'shorts' were making that side think it was lean.

 

i will have to check that also. just dont have the time or $ to change or check anything right right now. went out and drank it all away.

thanks again to everybody for their input!