I just purchased a 1994 blazer k5 sport. I went to change my oil and it was thin and smelled like gas. The truck is burning gas like crazy and there is smoke coming out the tail pipe. The truck also smells like gasoline while running. I had a compression test done and everything checked out. He said it appears I have a bad ring. I want to know what is my best alternative to fixing the problem. New engine? Rebuild kit? New rings? What the cheapest effective alternative?

 

I'm not 100% sure but I believe you have a TBI setup. I would highly suspect the injectors as leaking by. Gas can flow past tight piston ring no problem. My son-in-law has this exact same problem right now but hasn't looked into it, even though I've told him the same thing.

You can try running some injector cleaner through the tank for a few tank fulls and see if that helps.

 

When we bought my son's 91 Camaro it was doing similar things. Nasty exhaust that would make your eyes water if you stood around it very long.

Bought a throttle body rebuild kit and tore it apart and found the gaskets/o-rings in pretty bad shape. Used the appropriate parts out of the rebuild kit and it ran fine after that for about a year before a rod started knocking and we pulled the engine out.

 

Take the air cleaner off and shine a bright flashlight at the fuel spray. If it's dribbling like a faucet instead of spraying in a cone, that'll cause your problem.

get new injectors, or try injector cleaner and then do an injector rebuild kit (very easy).


If the injectors aren't at fault, you may have a sensor problem causing extreme rich condition. You can check by jumpering the OBD-I trouble code port and running the engine. It's the top row, two farthest right pins (A&B). The SES light will flash. When it warms up to closed loop, the flashing frequency (time on, and time off) will change. It indicates how rich/lean of a mixture the PCM is commanding. Time on/off should be about the same.

Check TPS voltage curve and CTS resistance.