The Ford Barn - View Single Post - Surging at idle with spark where it should be

30 Closed Cab PU · 03-26-2020, 09:39 AM

X2, usually on mine and the gav is set too rich I get some slight black exhaust.

Another possibility is the Carb Idle Mixture screw is set too rich. In extreme cases this can also cause a loud exhaust backfire (sound like a shotgun) when shutting off the motor, caused by unburned gas mixture in the exhaust manifold igniting.
If you pull a spark plug and the insulator is extremely black/sooty, you most likely are running rich.

03-26-2020, 09:39 AM	#9
30 Closed Cab PU Senior Member Join Date: Aug 2018 Posts: 2,332	Re: Surging at idle with spark where it should be X2, usually on mine and the gav is set too rich I get some slight black exhaust. Another possibility is the Carb Idle Mixture screw is set too rich. In extreme cases this can also cause a loud exhaust backfire (sound like a shotgun) when shutting off the motor, caused by unburned gas mixture in the exhaust manifold igniting. If you pull a spark plug and the insulator is extremely black/sooty, you most likely are running rich.