Rochester Quadrajet high rpm issues

[jnimety]

Hi all. I’m having issues with one of the engines on my F32. The engine doesn’t want to maintain RPMs at cruising speed. It runs fine at idle but will struggle to get to 3000 rpm, fall back to 2800, then surge to 3200 and back to 2800 seemingly at random. To make things worse we’re traveling about 5 hours from home port.

Any advice, ideas, links, etc are very much welcome. Thank you all for making this such a great forum.

270 Crusader
Rochester Quadrajet

[swampman]

is there any history of carb , fuel system or ignition work lately?

[jnimety]

No recent engine work. The boat did sit last year if that helps.

[prowlersfish]

Change your fuel filters and don't forget the one in the carburetor.

[jnimety]

Thanks! I’ll give that a try.

[jnimety]

I know about the primary fuel filter and the small cartridge/screen close to the carburetor. Is there another one in the carburetor?

[prowlersfish]

I know about the primary fuel filter and the small cartridge/screen close to the carburetor. Is there another one in the carburetor?

Yes, where the fuel line hooks up. Behind the big nut. Some have a filter others have a screen both can get plugged.

[jnimety]

Well… After 3 days of replacing fuel filters, finding and fixing a fuel leak, and test runs in between… no luck. As a last resort we changed the plugs and that fixed the issue. That little filter on the carb did have a fair amount of debris in it, so maybe it was a combination of things. Time for beer!