running rich

Quick_silver

Registered User
i have a 90 sc, with a 94 motor (94 blower, injectors, tb, coil pac, etc.) hollowed cats and flowmaster exhaust -mufflers. its running soo rich when i punch it, it smokes, and it leaves black around the tips, the old motor had a blown hg, could the oxygen sensors be bad? thanks for any and all input
 
Blown head gaskets can ruin the O2 sensors. I would think that they could be a very likely culprit. If your car has high miles on it and they are original I would consider changing them anyway. You might just get better fuel economy and more power to boot.

Bob
 
Something to consider..At WOT the computer ignores readings from the O2 sensors.

Problems with the O2 sensors will more often affect idle, part throttle and fuel economy, not cause a rich condition like you are describing.

I suggest you look at your MAF sensor wires and see if they are dirty. They can be cleaned with carb cleaner or similar cleaners.

Another area is the fuel pressure regulator. Pull the vacuum hose and make sure that fuel isn't leaking into the vacuum/boost signal hose. You may also want to check your fuel pressure to make sure it isn't to high and to make sure it's holding pressure after the pump is turned off.

If it's not holding pressure, the regulator or one of the injectors could be leaking.

David
 
update, i took it to autozone and had them read the codes, it read 35 and 67, one was pvc and exhaust pressure and the other was something about the heater being on he said. the guy told me the 90 computer wasnt used to the 94 injectors, tb, etc. etc. and told me to get a 94 e- prom and put in it, would that help? the car runs good but i keep having people telling me about it smoking, and i really hate the black on the tail pipes from this "running rich condition" thanks
 
Yeah, I am thinking that you are going to need the EEC and MAF from a '94 or '95 SC. That would explain your problem. Or you could get a tuner and you should be able to take care of that. I would choose the latter myself.

Thomas
 
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