454 starting issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**KyleSeal** · 08-11-2016, 10:49 AM

Background info: original 84 454 BBC with an Edelbrock intake with a Holley 750 Double Pumper (mechanical choke), big cam but other than that rather stock.

Problem: the other day I had an issues driving where it would studder under acceleration just after shifting. It shut off down the road and I tried to start it again and it was backfiring through the carburetor (white smoke) and just wouldn't start. I advanced the dist a few degrees and it fired up. But it throws white smoke from the pipe after advanced, so I assume its getting okay spark because it does start, just doesnt run great. I cannot find out whats wrong.

The main thing that gets me is that itll start good right after advancing the dist, but after that first start it doesn't start easy and will try to do a carb backfire again.

and heres a pic of the 84 K30 just for fun.

mac · 08-13-2016, 09:10 AM

Bet the dist advance mechanism has never been taken apart cleaned and lubed!

bilfman · 08-13-2016, 08:23 PM

White smoke equals coolant in the combustion chamber. So possibly intake/head gasket issue.

**KyleSeal** · 08-13-2016, 11:39 PM

I think I found some of the issue. The 750 I have is rated for a big cam, ported head, giant exhaust drag car. Doesnt do well at idle and likes WOT better. I moved it down to a 600 I had in my basement and it fired up good and ran pretty good. In the morning I will tune it better and see how it does. It was truly flooding the motor with the 750.

08-11-2016, 10:49 AM	#1
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	454 starting issues Background info: original 84 454 BBC with an Edelbrock intake with a Holley 750 Double Pumper (mechanical choke), big cam but other than that rather stock. Problem: the other day I had an issues driving where it would studder under acceleration just after shifting. It shut off down the road and I tried to start it again and it was backfiring through the carburetor (white smoke) and just wouldn't start. I advanced the dist a few degrees and it fired up. But it throws white smoke from the pipe after advanced, so I assume its getting okay spark because it does start, just doesnt run great. I cannot find out whats wrong. The main thing that gets me is that itll start good right after advancing the dist, but after that first start it doesn't start easy and will try to do a carb backfire again. and heres a pic of the 84 K30 just for fun. Attached Images __________________ "Sometimes I do serve as a good bad example. Glad to be of service." My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809

08-13-2016, 09:10 AM	#2
mac Active Member Join Date: Jan 2005 Location: Spokane WA Posts: 166	Re: 454 starting issues Bet the dist advance mechanism has never been taken apart cleaned and lubed!

08-13-2016, 08:23 PM	#3
bilfman Registered User Join Date: Dec 2011 Location: Regina, SK, Canada Posts: 622	Re: 454 starting issues White smoke equals coolant in the combustion chamber. So possibly intake/head gasket issue. __________________ 1979 Chevy Dually Crew 4X4 454, D60 Tru-trac, D70 Detroit Locker, 3.73, 4L80E/NP205 1971 GMC 3/4 Ton 4X4

08-13-2016, 11:39 PM	#4
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	Re: 454 starting issues I think I found some of the issue. The 750 I have is rated for a big cam, ported head, giant exhaust drag car. Doesnt do well at idle and likes WOT better. I moved it down to a 600 I had in my basement and it fired up good and ran pretty good. In the morning I will tune it better and see how it does. It was truly flooding the motor with the 750. __________________ "Sometimes I do serve as a good bad example. Glad to be of service." My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809



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