Holley Problem
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,429
Likes: 0
From: Tucson AZ
Holley Problem
I have a Holley 80508S vacuum secondary 750cfm carb on what I think is a stock 1971 LS5 454. After installing a GM Performance Parts intake, I have gas smell in the car. The entire fuel system has been changed to new except steel lines on the frame. The system has been tested with a smoke generator, no leaks. If I roll up the windows, no smell. I have 750-1000 miles on this carb, and rebuilt it. I found the metering block surfaces were just as any other Holley in the world, not flat and true. I machined them flat and took plenty of time and carb clean to blow thru all the orofices. I'm not too worried that I have trash in it. If you put your finger over the bowl vents, the front one will cause the engine to die, as it should. The rear vent tube causes the engine to die, but gas squirts up thru the vent and the rear squirters and die as well. I'm stumped like I never been stumped in 35 years. ANYONE?
CF Community Team
Joined: Oct 2004
Posts: 19,341
Likes: 5,232
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
I would spend $350.00 and bolt on a new carb. Every time I farted around with rebuilt carbs over the last 38 years I regretted it. Bolting on a new carb is the best way to stop the headaches. I just did this with my 68. No more headaches 
Unless this is already a new carb ?
Unless this is already a new carb ?
Heel & Toe
Joined: Sep 2007
Posts: 24
Likes: 0
Send your Holley in to Allstate Carburetor and let them rebuild it or give you a core credit for a new or rebuilt Holley. I did and could not be more happy. I have a 383 stroker crate engine in my '71 and I bought a zinc plated Allstate Carburetor tuned HP 4150 double pumper from them and it runs like a raped ape! They do great work and they are a Holley distributor. If you buy a rebuilt carb from them they use only Holley parts, no cheap Chinese crap! They also sell new...
Here is their website- http://www.allcarbs.com/
Here is their website- http://www.allcarbs.com/
Thread Starter
Melting Slicks
Joined: Sep 2007
Posts: 2,429
Likes: 0
From: Tucson AZ
Send your Holley in to Allstate Carburetor and let them rebuild it or give you a core credit for a new or rebuilt Holley. I did and could not be more happy. I have a 383 stroker crate engine in my '71 and I bought a zinc plated Allstate Carburetor tuned HP 4150 double pumper from them and it runs like a raped ape! They do great work and they are a Holley distributor. If you buy a rebuilt carb from them they use only Holley parts, no cheap Chinese crap! They also sell new...
Here is their website- http://www.allcarbs.com/
Here is their website- http://www.allcarbs.com/
There is a carb builder here in Tucson, I think Braswell, that are NASCAR carb builders. Not what I want, I want no gas smell. I'm still getting 10 MPG the way I drive it
Drifting
Joined: May 2004
Posts: 1,258
Likes: 0
From: Huntsville Alabama
I have that same carb on my yearone 350. I hate I have had nothing but problems with hesitation, idle, and gas smell. I think that carb is junk. I rebuilt my last friday hoping to fix some of the problems but it did not. Im thinking of tossing it and getting a 670 Street avenger.
