'70 402 fouled spark plug - Why? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

mosel70 · 08-13-2017, 11:49 PM

1970 C10, 402 with 454 heads. This spark plug is out of firing sequence #3 (second from front/drivers side). First plug is after about 100 miles. Second plug is after about 1500 miles (really gunked). I did a compression check and it was 115 psi dry, 114 psi wet. All other cylinders were 106 to 115 dry btw. Don't know how many miles are on the engine. It runs good outside an idle overtemp I'm dealing with (getting large CFM electric fans).

Would that kind of a fouled plug be a valve issue?

08-13-2017, 11:49 PM	#1
mosel70 Registered User Join Date: Jul 2016 Location: Las Vegas, NV Posts: 116	'70 402 fouled spark plug - Why? 1970 C10, 402 with 454 heads. This spark plug is out of firing sequence #3 (second from front/drivers side). First plug is after about 100 miles. Second plug is after about 1500 miles (really gunked). I did a compression check and it was 115 psi dry, 114 psi wet. All other cylinders were 106 to 115 dry btw. Don't know how many miles are on the engine. It runs good outside an idle overtemp I'm dealing with (getting large CFM electric fans). Would that kind of a fouled plug be a valve issue? Attached Images



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.