That's where I would look first.
'74 BB running like cr*p
Thread Starter
Cruising
Joined: Aug 2003
Posts: 13
Likes: 0
From: Tx.
'74 BB running like cr*p
My 74 bone stock 454 recently started running bad. Blowing out alot of soot on start up. Coughs and sputters. Backfires on occasion.
Anyone have an idea where I can start looking?
TIA.
Anyone have an idea where I can start looking?
TIA.
Racer
Joined: Oct 2010
Posts: 259
Likes: 3
From: Plano TX
Choke Pull Off
I'm assuming you're talking about a cold start.
If the choke flap is "closing" properly when cold, prior to starting, make sure the choke pull off is opening the flap some after the engine starts.
I have a Holley Street Avenger and had that trouble. Took me a while to locate the pull off adjustment but once I did it was an easy adjustment, and solved the problem.
Remove the air cleaner and right after it starts, jump around an slightly open the flap with your hand and see if that helps.
If the choke flap is "closing" properly when cold, prior to starting, make sure the choke pull off is opening the flap some after the engine starts.
I have a Holley Street Avenger and had that trouble. Took me a while to locate the pull off adjustment but once I did it was an easy adjustment, and solved the problem.
Remove the air cleaner and right after it starts, jump around an slightly open the flap with your hand and see if that helps.
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Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
My buddy just finished a 69 427 roadster with similar symptoms. Changed out all the valve springs, there were 3 broken ones. This is not a fun job with.power brakes. Because this Vette sat for long periods without being started the compressed springs took a set and failed when it was started after years of neglect.
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
Sounds to me like your choke pull off vacuum canister has failed. As soon as the cold engine starts, it should pull open the choke just a little bit- maybe 1/4". If that's not happening, check the pulloff motor with a vacuum gauge. It's on the front right side of your Quadrajet.
Thread Starter
Cruising
Joined: Aug 2003
Posts: 13
Likes: 0
From: Tx.
Sounds to me like your choke pull off vacuum canister has failed. As soon as the cold engine starts, it should pull open the choke just a little bit- maybe 1/4". If that's not happening, check the pulloff motor with a vacuum gauge. It's on the front right side of your Quadrajet.
