The Ford Barn

SteveR. · 10-18-2020, 10:26 PM

I have a new engine with maybe 80 miles on it, built by a reputable manufacturer. It has started intermittent backfiring "fits" and corresponding power loss after it gets warm. I don't think it is the distributor or ignition, timing is correct, point gap is .020. Wondering if it is a stuck valve, is that common or likely for a new engine? What is the easiest way to check?

I checked between the upper and lower distributor plates, don't think there is a short there. Distributor worked fine with the prior engine. Low RPM & low load it runs fine, but when hot, it will intermittently run OK, then go into a fit of lost power & backfiring. Enrichening the GAV might help slightly, but the problem remains.

10-18-2020, 10:26 PM	#1
SteveR. Member Join Date: Nov 2017 Location: Aledo, TX Posts: 63	New engine - intermittent backfiring - stuck valve? I have a new engine with maybe 80 miles on it, built by a reputable manufacturer. It has started intermittent backfiring "fits" and corresponding power loss after it gets warm. I don't think it is the distributor or ignition, timing is correct, point gap is .020. Wondering if it is a stuck valve, is that common or likely for a new engine? What is the easiest way to check? I checked between the upper and lower distributor plates, don't think there is a short there. Distributor worked fine with the prior engine. Low RPM & low load it runs fine, but when hot, it will intermittently run OK, then go into a fit of lost power & backfiring. Enrichening the GAV might help slightly, but the problem remains.