carb is loading up on me - The 1947 - Present Chevrolet & GMC Truck Message Board Network

crm318 · 10-13-2008, 06:54 PM

i just installed a a quadrajet that i just rebuilt and im having an extremely rich condition, the truck ran fine in town and then i took it for a 30 mile highway drive which was also good. when i got off the highway and into town, i noticed that the truck began to bog and smoke a bit at idle, it was ok if i kept the rpms up. i disassembled it and everything checked out. there was also no debris in the bowl or needle/seat area. i bent the float to lower it and put everything back together. it still has the same symptoms. i did notice that the little tiny clip for the needle to hang on the float was missing. is that a big deal? i have heard of many guys running without them. what other things could cause this flooding?

crm318 · 10-14-2008, 02:04 PM

anyone?

77 350 Shorty Wide · 10-14-2008, 02:22 PM

It's possible the new needle & seat are defective. You did install a new one didn't you? Fuel pump pressure is to high. Something stuck in the needle and seat. Are your idle screw adjustments right? Lot's of places to look. Good lick & God Bless, Terry

Sorry just saw you looked for debris in the seat.

crm318 · 10-14-2008, 04:23 PM

i guess ill have a look at the idle screws. ill let ya know.

Myself · 10-16-2008, 04:07 PM

I have heard older Quadrajets like to leak out of the soft plugs on the bottom side of the carb.

crm318 · 10-16-2008, 07:47 PM

i have mine apoxyed.

primered_junk · 10-16-2008, 10:17 PM

Fuel pressure is a big deal on q-jets, they don't like it. Also check the bushings in the throttle plate, if they wear it turns into a vacuum leak. Check for vacuum leaks as they could cause a rich idle (belive it or not) Check the choke pull off and make sure the "flap" is not falling closed, and also make sure the "butterflies" on the secondarys are binding and hanging slightly open.

10-13-2008, 06:54 PM	#1
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	carb is loading up on me i just installed a a quadrajet that i just rebuilt and im having an extremely rich condition, the truck ran fine in town and then i took it for a 30 mile highway drive which was also good. when i got off the highway and into town, i noticed that the truck began to bog and smoke a bit at idle, it was ok if i kept the rpms up. i disassembled it and everything checked out. there was also no debris in the bowl or needle/seat area. i bent the float to lower it and put everything back together. it still has the same symptoms. i did notice that the little tiny clip for the needle to hang on the float was missing. is that a big deal? i have heard of many guys running without them. what other things could cause this flooding? __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-14-2008, 02:04 PM	#2
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: carb is loading up on me anyone? __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-14-2008, 02:22 PM	#3
77 350 Shorty Wide Registered User Join Date: Dec 2006 Location: Yakima, WA Posts: 325	Re: carb is loading up on me It's possible the new needle & seat are defective. You did install a new one didn't you? Fuel pump pressure is to high. Something stuck in the needle and seat. Are your idle screw adjustments right? Lot's of places to look. Good lick & God Bless, Terry Sorry just saw you looked for debris in the seat. Last edited by 77 350 Shorty Wide; 10-14-2008 at 02:23 PM.

10-14-2008, 04:23 PM	#4
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: carb is loading up on me i guess ill have a look at the idle screws. ill let ya know. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-16-2008, 04:07 PM	#5
Myself Registered User Join Date: Oct 2005 Location: Northern Arkansas Posts: 1,127	Re: carb is loading up on me I have heard older Quadrajets like to leak out of the soft plugs on the bottom side of the carb.

10-16-2008, 07:47 PM	#6
crm318 Alright Alright Alright Join Date: Mar 2004 Location: Midland, Texas Posts: 1,672	Re: carb is loading up on me i have mine apoxyed. __________________ 1972 Cheyenne Chevrolet red and white 357ci, Vortec heads, GM Performance high rise intake, Comp 268H .454/.454 218/218 110 LSA Quadrajet carb, Flowtech headers, 2.25 40 series HEI, Curve kit, TH 350, 3.07 gears 275/60/15s on 15x8 rallies

10-16-2008, 10:17 PM	#7
primered_junk ASE master tech/machinist Join Date: May 2008 Location: Blue Mound Texas Posts: 303	Re: carb is loading up on me Fuel pressure is a big deal on q-jets, they don't like it. Also check the bushings in the throttle plate, if they wear it turns into a vacuum leak. Check for vacuum leaks as they could cause a rich idle (belive it or not) Check the choke pull off and make sure the "flap" is not falling closed, and also make sure the "butterflies" on the secondarys are binding and hanging slightly open. __________________ "I sit here and I pray in my broken down Chevrolet....."



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