[DESPERADO]

I have a 350 chevy when motor cold runs great but when it warms up it back fires and will hardly run. I have replaced the rotor dis cap plug wires. ANY HELP???

[speed123]

Could be a few things, but I don't think there is a problem with the distributer. If the engine has high miles, your timing chain is probably worn and is stretching when hot, or the camshaft could be worn.

[Mertz]

Could also be a sticky valve or carbon deposits behind the valves. I used some heavy duty carbon cleaner in my 400 and it would backfire everytime I punched the gas. After the carbon worked itself out it quit. I knew that I had to run the car to remove the carbon but did not expect all the backfire. The more I drove it the better it got. I had some backfire before I did this and suspected a sticky valve or carbon behind a valve. That's why I did the cleaning. It seemed to help. A corvair trick and it seems to work on my 350 is to run the engine at about 1500 to 2000 and pour water down the carb. I did this on the 350 and it ran much smoother. I used a garden sprayer and sprayed it into the carb until it ran better.

[F-1Rodder]

Check for vacuum leaks. Check your timing.