mikemassi

(94 Z28 100,000 miles) my car has a problem and im not 100% sure what it is. the car is running a little rough and there is a smell of gas like its running really rich. i just replaced all plugs and tomorrow im replacing all the wires. i noticed number 8 wire has a little cut in it could that be the problem? the RPMs are steady and im pretty sure its not optispark. any suggestions?

Injuneer

A misfire will cause it to run rich. A cut in the insulation of a wire carrying 20-30,000 volts is most likely causing problems.

A scan data log would probably show you if the misfire is causing elevated BLM's, or if running rich is causing the misfire.

You might want to add specific info regarding any mods to the engine, what parts have been replaced, etc.

mikemassi

ok so yesterday i went thru and replaced all the plug wires and checked all the plugs. everyhting is pretty much brand new but the car is still running like crap. its real choppy and u can hear the motor pinging wen it shifts into second until the rpms get up to 3grand. the exhuast smells like gas and alcohol. can anyone give me some kind of idea of what this could be? ignition coil...opti..injectors? thank u

Injuneer

If you hear "pinging", you may have a serious timing problem. The knock sensor circuit should react fast enough so that you never hear knock or ping. Have you tried using higher octane fuel to eliminate the noise?

Is it possible what you say is an "alcohol" smell is actually burning coolant? When you checked the plugs, were any of them exceptionally clean?

mrmint69

Have you changed the O2's or the opti before? If they are original they might be going out but its hard to say. Do you have a check engine light? Have you done anything like headers or other mods?