C2 Side Exhaust Popping

[Ralph E.]

My side pipe exhaust are popping during de-acceleration and coasting. Any ideas why? The engine is a 327/300. I should add, this past winter I removed and replaced the intake, distributor and carburetor.

[john38706]

Re: C2 Side Exhaust Popping

you need to check for vacumm leaks.

[Ralph E.]

Re: C2 Side Exhaust Popping

How?

[Michael H.]

Re: C2 Side Exhaust Popping

Here's a good way to check for intake leaks. With the engine warmed up and running at idle, spray some carb cleaner or ether around the base of the carburetor, intake manifold, etc. If the engine RPM changes, that means wherever you were spraying has a leak.

[Ralph E.]

Re: C2 Side Exhaust Popping

The engine has a steady idle at 750RPM. But I'll give it a try.

[Duke W.]

Re: C2 Side Exhaust Popping

Afterfiring through the exhaust on overrun is usually a sign of lean mixture, so checking for vacuum leaks as stated is a good idea. If none are found the idle mixture should be richened.

A 300 HP engine should idle butter smooth at 500 RPM. If it won't idle smoothly at this speed, the cam has probably been changed, but the carb should still be able to deliver a proper idle mixture.

Why did you R&I the intake, carb. and dist.?

Duke

[Ralph E.]

Re: C2 Side Exhaust Popping

I changed the intake manifold. When I bought the car I checked the date, but I didn't check the p/n. Dumb! The lean mix sounds more like my problem. How do I lean the carburetor mix?

[Duke W.]

Re: C2 Side Exhaust Popping

If the mixture is lean it needs to be richened. Refer to your service manual and perform the idle speed and mixture adjustment.

Duke

[Ralph E.]

Re: C2 Side Exhaust Popping *THANKS*

Thanks Duke. I should have look in the Service Manual before I even posted. I was in work reading these post.