What the **** is wrong with my carb - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1974ChevyC10 · 12-23-2004, 06:22 PM

over the last couple days my carb-carter afb 600-when i start the truck its fine but the minute i step on the gas the fast idle kicks in and all but then it sticks open-wont go off when i left off the throttle.im sure its not the throttle linkage as ive checked it when the vehicle is off and it returns fine.it also sticks open whether its warm or cold.im not sure whats going on so im trying to find out if its something that can be fixed or is it new carb time come payday next week.please help me out.

Slonaker · 12-23-2004, 07:06 PM

I'm not sure what your setup is, but I had a problem like that once. I have an A/C truck, and the compressor was nonfunctional. When it got cold out, I would turn on the defroster. It would bump up the idle to compensate for the compressor that no longer had a belt on it. Nothing would happen until I hit the gas first time, then the idle would shoot up. Just a thought...

Slonaker

TrainD5115 · 12-24-2004, 12:42 AM

I had a similer problem on my 79 with regard to the high idle solenoid. It would kick the idle way up when I used the defrost. Ending up taking it off as the A/C was long since dead anyway. Also you might want to check out the air spring wind up screw below the choke cover housing. On my Rochester 4bbl, the high idle cam would not kick down if the screw was turned in too far. Hope this helps some, I know how frustrating a tempermental carb is.

Train

blaserman · 12-24-2004, 04:05 AM

Sounds Like Your Choke Release Is Not Working. Try Cleaning The Arear Oof And They Spray Some Silcone Lub On It. That Worked On My 950 When It Did The Same Thing.

1974ChevyC10 · 12-26-2004, 12:21 PM

my truck is a factory non-ac model with a carter afb-i dont have a qjet on it.me and my dad checked it out yesterday while he was in town-turns out when the truck was running the throttle would stick partially open due to a weak throttle return spring.its got a new one now and is good to go

TrainD5115 · 12-26-2004, 09:36 PM

Good deal...I may try that for mine. It still idles a wee bit higher than it should. If I take my hand to the throttle linkage it will idle down all the way.

12-23-2004, 06:22 PM	#1
1974ChevyC10 Overworked and Underlaid Join Date: May 2002 Location: Flagstaff,Arizona Posts: 1,279	What the is wrong with my carb over the last couple days my carb-carter afb 600-when i start the truck its fine but the minute i step on the gas the fast idle kicks in and all but then it sticks open-wont go off when i left off the throttle.im sure its not the throttle linkage as ive checked it when the vehicle is off and it returns fine.it also sticks open whether its warm or cold.im not sure whats going on so im trying to find out if its something that can be fixed or is it new carb time come payday next week.please help me out. __________________ I'd rather push a Chevy than drive a Ford The Beast-1978 C10 LWB Red-1978 C10 LWB (Uncle Mike)Michael Henry Millett 11/5/1957 to 03/08/2012 Gone but will never be forgotten-RIP (Uncle Chuck)Charles Manning Gulbronsen Sr 1956-2012 Taken from us to soon but you will live on in our hearts-RIP

12-23-2004, 07:06 PM	#2
Slonaker Insert Witty Text Here Join Date: Oct 2002 Location: San Antonio, TX Posts: 3,415	I'm not sure what your setup is, but I had a problem like that once. I have an A/C truck, and the compressor was nonfunctional. When it got cold out, I would turn on the defroster. It would bump up the idle to compensate for the compressor that no longer had a belt on it. Nothing would happen until I hit the gas first time, then the idle would shoot up. Just a thought... Slonaker __________________ '86 Chevy C10 (Sold 04/19/13 ) Stock '01 Silverado

12-24-2004, 12:42 AM	#3
TrainD5115 North Coast, baby! Join Date: Jun 2004 Location: Toledo, OH Posts: 437	I had a similer problem on my 79 with regard to the high idle solenoid. It would kick the idle way up when I used the defrost. Ending up taking it off as the A/C was long since dead anyway. Also you might want to check out the air spring wind up screw below the choke cover housing. On my Rochester 4bbl, the high idle cam would not kick down if the screw was turned in too far. Hope this helps some, I know how frustrating a tempermental carb is. Train __________________ Brad 79 Scottsdale C20 350/350 3.73's Still running full CA smog gear!

12-26-2004, 12:21 PM	#5
1974ChevyC10 Overworked and Underlaid Join Date: May 2002 Location: Flagstaff,Arizona Posts: 1,279	my truck is a factory non-ac model with a carter afb-i dont have a qjet on it.me and my dad checked it out yesterday while he was in town-turns out when the truck was running the throttle would stick partially open due to a weak throttle return spring.its got a new one now and is good to go __________________ I'd rather push a Chevy than drive a Ford The Beast-1978 C10 LWB Red-1978 C10 LWB (Uncle Mike)Michael Henry Millett 11/5/1957 to 03/08/2012 Gone but will never be forgotten-RIP (Uncle Chuck)Charles Manning Gulbronsen Sr 1956-2012 Taken from us to soon but you will live on in our hearts-RIP

12-26-2004, 09:36 PM	#6
TrainD5115 North Coast, baby! Join Date: Jun 2004 Location: Toledo, OH Posts: 437	Good deal...I may try that for mine. It still idles a wee bit higher than it should. If I take my hand to the throttle linkage it will idle down all the way. __________________ Brad 79 Scottsdale C20 350/350 3.73's Still running full CA smog gear!

12-24-2004, 04:05 AM	#4
blaserman Senior Member Join Date: Nov 2004 Location: glen burnie md Posts: 447	Sounds Like Your Choke Release Is Not Working. Try Cleaning The Arear Oof And They Spray Some Silcone Lub On It. That Worked On My 950 When It Did The Same Thing.



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