Hi my name is Tyler, i drive a 1988 K2500 P/U. I've got a 5.7L 350 i just bought as a crate motor last year. it came stock as a Throttle Body Injection (TBI) i just recently Carburated it with an Edlebrock 750. after tearing the heads off of it and cleaning em up. i just got it running the again yesterday and after getting everything figured out, it knocks when the motor is under touqe or when i just punch the throttle from idle in short burst, and also around 2500 to 3500 rpm. its not exactly a knock it sounds like a diesel, when it makes this noise. its not timed perfect but its as close as i can get it by ear with out a timing light because of the MSD Distributor. any idea on what it could be would be greatly appreciated.

 

Welcome to the forum. Are you talking about spark knock? The list of suspects include too much ignition advance (knock sensor inoperative?), too high a cylinder compression ratio, low octane fuel, etc.

 

Hi Harvey70,

Welcome to the Chevy Forums.

I moved your thread to the proper section.

Why don't you read the rules, and re-post in the

"Welcome" section?

 

Hmmm, I drove a 454 one time where it sounded similar. Apparently the sound was that of the fuel injection system. It would only do that under load and it sounded like a diesel rattle but it was the fuel injectors making all that noise. I dont know if it is bad or not.

 

retard the timing some more, try again, or get a darn timing light

but pretty sure its to advanced

 

Thanks therewolf I didn't know what to do. It was the timing to advance I finally broke down and invested in a timing light, thanks every one