Carb help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Troy Campbell · 01-10-2009, 10:09 PM

Hey guys, I have a 71 chevy swb p/u with a 402 BB. I have a Elerbrock 600 carb on it and when i ease into the gas, she will fly. When i get on it quickly, the engine wants to bog down and backfire through the carb. I had just got the timing checked and it was right were it needed to be. Also i replaced the alt with one that has an internal regulator, i did my rewiring according to Todd, i have 4 wires going into the back of the alt. I have a red, blue, white and a ground that bolted up to the back of the alt. Do i need this ground wire or can i discard it. Thank you indavance.

hilandr452 · 01-10-2009, 10:13 PM

Did it run well before you replaced the alternator? When you say 600 edelbrock, you mean 600 cfm? I'm running an edelbrock 800 CFM on mine and it responds well when I floor it.

Dan

Troy Campbell · 01-10-2009, 10:18 PM

Yes sir it is a 600 cfm. This running problem was before i replaced the alt. I have not started it since replacing the alt, i am still waiting for parts to be chromed before i put it back together.

**VetteVet** · 01-10-2009, 10:31 PM

Sounds to me like you need to adjust the accelerator pump linkage on the carb and maybe richen up the off idle circuit.
The ground wire you speak of was routed to the external voltage regulator so as long as the alternator has a good ground back to battery negative you should be fine. Mounting it to the block should be all the ground it needs.

68C15 · 01-10-2009, 10:46 PM

are the secondaries opening too fast? a common problem with heavy trucks,automatic trannies, and low numbered gears.
if its a Thunder Series AVS then it is adjustable. check the carb manual.

01-10-2009, 10:09 PM	#1
Troy Campbell Registered User Join Date: Jul 2008 Location: Sugar Land Texas Posts: 22	Carb help Hey guys, I have a 71 chevy swb p/u with a 402 BB. I have a Elerbrock 600 carb on it and when i ease into the gas, she will fly. When i get on it quickly, the engine wants to bog down and backfire through the carb. I had just got the timing checked and it was right were it needed to be. Also i replaced the alt with one that has an internal regulator, i did my rewiring according to Todd, i have 4 wires going into the back of the alt. I have a red, blue, white and a ground that bolted up to the back of the alt. Do i need this ground wire or can i discard it. Thank you indavance.

01-10-2009, 10:13 PM	#2
hilandr452 Registered User Join Date: Jan 2009 Location: Colorado Springs, CO Posts: 357	Re: Carb help Did it run well before you replaced the alternator? When you say 600 edelbrock, you mean 600 cfm? I'm running an edelbrock 800 CFM on mine and it responds well when I floor it. Dan __________________ Dan Smith Colorado Springs, CO 71 GMC Custom Camper "Longhorn" 454, TH400 73 Chevy Camper Special (Yes, it's badged a camper special) Flat Bed Motorhome conversion 454, standard tranny *"DON'T TREAD ON ME !!!"* My Project: http://www.picturetrail.com/sfx/album/view/20829244 , http://www.picturetrail.com/sfx/album/view/24654442

01-10-2009, 10:18 PM	#3
Troy Campbell Registered User Join Date: Jul 2008 Location: Sugar Land Texas Posts: 22	Re: Carb help Yes sir it is a 600 cfm. This running problem was before i replaced the alt. I have not started it since replacing the alt, i am still waiting for parts to be chromed before i put it back together.

01-10-2009, 10:31 PM	#4
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,718	Re: Carb help Sounds to me like you need to adjust the accelerator pump linkage on the carb and maybe richen up the off idle circuit. The ground wire you speak of was routed to the external voltage regulator so as long as the alternator has a good ground back to battery negative you should be fine. Mounting it to the block should be all the ground it needs. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

01-10-2009, 10:46 PM	#5
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: Carb help are the secondaries opening too fast? a common problem with heavy trucks,automatic trannies, and low numbered gears. if its a Thunder Series AVS then it is adjustable. check the carb manual.



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