Backfire problem

I am still having problems with my chevy 350 backfiring.

I have replaced the distributor, cap, rotor, wires, plugs, fuel pump (that was fun :rolleyes: ), fuel fliter, air filter, o2 sensor and removed the catalitic (also fun).

The timming looks to be right. Compresion is between 150- 160 on all cylinders.

When running at any throttle, except idle, the engine runs strong. At idle , it has mutilple backfires. "puh, puh........puh, puh, puh......puh, puh......phu,puh,puh."

So I have fuel, fire, air, and good compresion.

What else could cause the engine to lose power when it backfires? It is actually starting to stall becasue of the loss of power.

Thanks for any sugesstions

Charles

Check valve lift. Could be GM's famous self-destruct camshaft.

Um, what? :eek:

I did forget to mention that the truck has 1509?? miles on it.

If it is an internal problem, I guess replacing the engine is more cost effective than repair. Yes?

I don't have the time or the knowledge for a teardown and rebuild.

150 thousand miles. I don't recall the last three.

"Usually means a valve problem. "

Great. what does repairing that entail?

Update:

The backfire problem was caused by a cracked spark plug go figure.
:HMMM:

Hrm, I did use the plug socket. I think it was cracked in the box.