I recently purchased a 1994 Trans Am with the LT-1 engine in it. The guy I bought it from said it smoked and was running rich, so I took it to a mechanic and he looked at it and gave me a list of stuff wrong with it, intake gasket leaking, he said it needs a new opti spark, new oxygen sensors, it runs fines, idles a little rough, but clears out right away as soon as you take off, but when accelreated hard it smokes black real bad. It had a new recent tune up with new plugs and wires, I am just wondering where to start at? I am going to have to do a little bit at a time due to money constraints. Where should I start first? It also needs other stuff, rear rotors and brakes, new rear end bearings, and some other small stuff. Any help or suggestions will be appreciated. Thanks in advance.

 

Start with the optispark and the O2 sensors, that should lean your car out. Good luck.

 

I would start cheap, like the intake gasket and O2's. Every mechanic you take it to is going to automatically tell you it's the opti because of the high dollar replacement. Do the intake gasket and the O2's yourself, then take it from there.

 

What kind of milage are we talking? Is it a modded car or pretty much stock?

My rich condition was caused by a broken bolt on the exhaust manifold. It was passing outside air across the Bank 2 O2 and telling the computer that it was running lean. The computer in turn was cranking up the injector pulse width to compensate for a "false" lean condition. Thus actually running Bank 2 extremely rich. Like in eventually burnt up the cat rich.

These broken bolts seem pretty common around here, might want to look for an exhaust leak of some kind.

Best way would be to get a comprehensive scan and post it here for others to analyze.

Good luck
Sean

 

ok thanks guys, i am new to the lt-1, basically lost on it, going to try to find a good, trustworthy (almost impossible) mechanic to do the work, i dont have the time or knowledge to do the work myself.