I have a bad miss problem after the car heats up. I replaced the opti last night...as in the distrubutor part from oreillys (I did the cap and rotor last fall).

Anyways, the car seems to run fine on cold start ups, but starts to sputter and miss throughout the rpm range once warm. I've recently replaced the coil, coil wire, spark plugs, and fuel filter. I've checked for vaccum and exhaust leaks. I got an SES light saying someting about "running lean on the right bank" before I did the opti. The light went off and didn't turn back on even before I did the opti install.

Any chance it could be the spark plug wires? I didnt' see any arching last night, but can the wires be bad without any visible damage? The wires aren't that old, but I guess the headers could have still nuked them.

Are O2s a possibilty since it does it after the car heats up?

How about fuel pump? I dont' have hard starts or anything. Is there still a possibility the pump could be messed up? We'll probably do a fuel pressure check tonight.

I've also tried unplugging the MAF, but the problem is still there.

Any thoughts or help appreciated. Thanks.

Brad

 

I would start with your O2 sensors since the light said lean. It could be wires they can go bad without and visible damage. I don't think it's your fuel pump that dosen't sound right.

 

Fuel pump kinda sounds like a long shot, but i've heard of it giving similiar symptoms as what i've got when it's going out.

I probably do a fuel pressure check tonight and then try some wires and O2s tomorrow. hopefully, i'll get this figured out soon.

 

hmmm, pulling the plug on the MAF should have forced it into open loop. When that happens, the o2's are out of the picture (no feedback). It could be the plug wires. IMHO, if it was injectors or fuel pump, it would do it all the time, not just warm. Plugs and wires is where I would go next.

 

yep, i agree. It still won't hurt to do a fuel pressure test to rule it out at least. I wasn't sure if the 02s were ignored when the MAF was unplugged, so I guess that prob is ruled out as well.

The plugs are 1week old. I tried that before the opti Wires will be my next step. I just would expect them to arch or show some signs of ware if they were jacked up

I still have a bad feeling about that oreillys opti...heard too many horror stories. i probably should have went with a GM one to make absolutely sure it wasn't the prob.

 

Have you checked your ign module?

 

not yet, i will probably do it tomorrow

 

btw, what are the general symptoms for a bad ign module?

 

Check your tailpipes for excess moisture, and your radiator for bubbles. It might be a blown head gasket. My car had the same symptoms as yours and that was the problem. It was EMBARRASING to run the 1/4 in Bowling Green at the F-body show due to the gaskets. Both of mine were blown.

 

hmmm, possiblitly. I will look into it. if the head gaskets was blown, wouldn't it cause problems even when the car is cold?

 

A symtom of a bad ign module is missing and sometimes not even starting.

 

its the 02's. the guy who posted a couple posts down has the same problem.

 

could you give me the thread link plz? it's hard to keep up with any thread on this board Anyways, i will probably go check 02s and ign this afternoon.

I did unplug the MAF. Wouldn't that cause the O2s to be ignored?