Do I need to rebuild the my carb? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Nima · 12-19-2008, 08:22 PM

Hello:
I have an edlebrock 1406 (electric choke) which is runing very rich. I was told before on this board that I have to change the main jets. Now, it has been a while that carb spits at the first gear when truck wants to take off, also it back fires. I am at 12-15 degree advance. I don't think my engine (a 350 out of what I don't know!) is anything special,my truck just came with it. I also change my point type distributor to mallory HEI few weeks ago if that mean anything. Thanks.

**LockDoc** · 12-19-2008, 10:05 PM

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I don't know a lot about carbs or what kind of adjustments the Edelbrock has so I can't help there but it seems to me that 12-15º advance is a little steep for a stock 350ci small block. I would think 8-10º would be a better number and make sure it is set with the vacuum advance hose off and plugged.

Did you re-gap your plugs when you put the HEI in?

LockDoc
.

Nima · 12-20-2008, 09:22 PM

Why the carb pups though? Is it just because the advance issue or it could be accelator pump assembly in the carb.

yotaforce · 12-21-2008, 12:22 AM

Have you "played" with your timing any? Adjust, drive, adjust, drive...? Vac. advance?

Wrenchbender Ret · 12-21-2008, 11:45 AM

A quick check of the accel. pump. With the engine off look down the throat of the carb & move the throttle from the idle position. There should be 2 squirts of gas go in the throats. If not or it just dribbles, the accel. pump is bad. Take out a spark plug or 2 after being driven. If there is black carbon on the porcelan it is probably running rich. With the engine idling slowly turn the idle jets, one at a time, in till the engine starts to slow down. Then back it out about 1/2 turn till it runs the smoothest.

12-19-2008, 08:22 PM	#1
Nima Blue 67 Join Date: Apr 2004 Location: Western WA Posts: 1,179	Do I need to rebuild the my carb? Hello: I have an edlebrock 1406 (electric choke) which is runing very rich. I was told before on this board that I have to change the main jets. Now, it has been a while that carb spits at the first gear when truck wants to take off, also it back fires. I am at 12-15 degree advance. I don't think my engine (a 350 out of what I don't know!) is anything special,my truck just came with it. I also change my point type distributor to mallory HEI few weeks ago if that mean anything. Thanks. __________________ 1953 GMC 3/4 ton: current project 1967 C20: 5.3 voretc with T5 conversion, 4 wheel 8 lug disc brake 1972 Nova: my 4 door sport sedan! 5.3 voretc + T5 conversion. drivable project, FUN!! 1979 Camaro Z28: 5.3 vortec conversion with build TH350: drivable project, Fun to drive 1992 Camaro RS convertible (Z28 clone): 5.3 conversion with build T5: on going project 2005 Silverado 2500, 4x4 Duramax, original owner

12-19-2008, 10:05 PM	#2
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,818	Re: Do I need to rebuild the my carb? - I don't know a lot about carbs or what kind of adjustments the Edelbrock has so I can't help there but it seems to me that 12-15º advance is a little steep for a stock 350ci small block. I would think 8-10º would be a better number and make sure it is set with the vacuum advance hose off and plugged. Did you re-gap your plugs when you put the HEI in? LockDoc . __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - Last edited by LockDoc; 12-19-2008 at 10:07 PM.

12-20-2008, 09:22 PM	#3
Nima Blue 67 Join Date: Apr 2004 Location: Western WA Posts: 1,179	Re: Do I need to rebuild my carb? Why the carb pups though? Is it just because the advance issue or it could be accelator pump assembly in the carb. __________________ 1953 GMC 3/4 ton: current project 1967 C20: 5.3 voretc with T5 conversion, 4 wheel 8 lug disc brake 1972 Nova: my 4 door sport sedan! 5.3 voretc + T5 conversion. drivable project, FUN!! 1979 Camaro Z28: 5.3 vortec conversion with build TH350: drivable project, Fun to drive 1992 Camaro RS convertible (Z28 clone): 5.3 conversion with build T5: on going project 2005 Silverado 2500, 4x4 Duramax, original owner

12-21-2008, 12:22 AM	#4
yotaforce Registered User Join Date: Oct 2007 Location: Rutherfordton, NC Posts: 89	Re: Do I need to rebuild the my carb? Have you "played" with your timing any? Adjust, drive, adjust, drive...? Vac. advance?

12-21-2008, 11:45 AM	#5
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: Do I need to rebuild the my carb? A quick check of the accel. pump. With the engine off look down the throat of the carb & move the throttle from the idle position. There should be 2 squirts of gas go in the throats. If not or it just dribbles, the accel. pump is bad. Take out a spark plug or 2 after being driven. If there is black carbon on the porcelan it is probably running rich. With the engine idling slowly turn the idle jets, one at a time, in till the engine starts to slow down. Then back it out about 1/2 turn till it runs the smoothest.



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