Holley Carb Problem-Need Help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

the-wreck · 10-08-2002, 06:18 PM

Hello
Trying to get my 69 finished. I have a 600 cfm vac. secondary Holley with almost zero miles on it. Put it on the truck and it runs pretty rich. Then it floods and stalls like the float is stuck. Take the frt, bowel off and it looks clean, everything moves correctly and the float looks fine as well as the float setting . Put it together and the same thing floods over-through the veture by the choke horn. What could be the problem? Id hate to replace this at this point. Thank you

sbrban · 10-08-2002, 06:34 PM

I've got a holley 3310 and I put a fuel regulator on the fuel line before it goes into the carb don't know if it would make a difference or not but I at least know how much fuel I'm dumpin' in the carb.

Alaskan · 10-08-2002, 06:39 PM

Check the needle and seat, might just be dirt stuck in it or the float could be leaking, to check just remove it from the bowl and shake it. Lastly check the fuel pressure at the carb should be 7 to 10 psi if I remember rite. To much and it will get by the seat.

crazy longhorn · 10-08-2002, 06:40 PM

On your o-1850 600, have you had bowls off?......check to see if the bouyancy spring has bounced out that goes under the float......that will cause a big flood over problem. good luck.....crazy longhorn

Gene · 10-08-2002, 06:48 PM

sbrban is absolutely right, put a regulator or a fuel pressure gauge inline to carb. because holleys are notorious for having fuel pressure problems, most street holleys are only capable of handling 7 psi. and some stock fuel pumps put out more than that. When this happens the fuel blows past the needle and causes flooding.. I have an Edelbrock 600 and have had none of these problems and have never set my float but holleys are good too when set correctly.

the-wreck · 10-09-2002, 06:22 AM

Thanks guys. I will check the above mentioned items. I was thinking I may have too much fule pressure, howerver, I have used lots of Holleys over time and never had one fllod over like this due to fp. Then again it could happen.

67shortie · 10-09-2002, 06:40 AM

Ya, holley should have 6-7 psi, no more. The one common problem I have run into with the symtoms you describe is a float that is set too high or a needle and seat that has dirt in it as others have suggested here.
To check the float, run the engine (if possible) pull the sight plug off of the bowl, the fuel level should be just at the bottom edge of the sight hole. If it is pouring out uncontrolably, shut the engine off and pull the needle and seat out of the bowl by unscrewing the top of the assembley on top of the bowl fuel inlet. You don't have to pull the whole bowl off of the metering block possibly wasting a gasket and a bowl full of fuel. Look for dirt, even the slightest bit of it will screw thing up in a major way. If clean, screw it back in, adjust it to get a static level (approx) and fire the engine. Recheck the sight plug method and raise/lower as nessassary.

10-08-2002, 06:18 PM	#1
the-wreck Registered User Join Date: Sep 2001 Location: LI New York Posts: 159	Holley Carb Problem-Need Help Hello Trying to get my 69 finished. I have a 600 cfm vac. secondary Holley with almost zero miles on it. Put it on the truck and it runs pretty rich. Then it floods and stalls like the float is stuck. Take the frt, bowel off and it looks clean, everything moves correctly and the float looks fine as well as the float setting . Put it together and the same thing floods over-through the veture by the choke horn. What could be the problem? Id hate to replace this at this point. Thank you

10-08-2002, 06:34 PM	#2
sbrban Registered User Join Date: Sep 2002 Location: Iowa Posts: 236	I've got a holley 3310 and I put a fuel regulator on the fuel line before it goes into the carb don't know if it would make a difference or not but I at least know how much fuel I'm dumpin' in the carb. __________________ you never have too many suburbans....

10-08-2002, 06:39 PM	#3
Alaskan Truck'n the alcan Join Date: Jan 2001 Location: Houston, AK Posts: 149	Check the needle and seat, might just be dirt stuck in it or the float could be leaking, to check just remove it from the bowl and shake it. Lastly check the fuel pressure at the carb should be 7 to 10 psi if I remember rite. To much and it will get by the seat. __________________ 68 GMC 4x4 71 C20 Custom Deluxe 83 1/2 ton conversion van Last edited by Alaskan; 10-09-2002 at 07:14 AM.

10-08-2002, 06:48 PM	#5
Gene Registered User Join Date: Aug 2002 Location: Muskogee, Oklahoma Posts: 2,914	sbrban is absolutely right, put a regulator or a fuel pressure gauge inline to carb. because holleys are notorious for having fuel pressure problems, most street holleys are only capable of handling 7 psi. and some stock fuel pumps put out more than that. When this happens the fuel blows past the needle and causes flooding.. I have an Edelbrock 600 and have had none of these problems and have never set my float but holleys are good too when set correctly. __________________ 1971 SWB 4X4 Build BOARD MEMBER #5448 BOOMER SOONER!!!!

10-09-2002, 06:40 AM	#7
67shortie Green club Join Date: May 2002 Location: Central CA Posts: 1,059	Ya, holley should have 6-7 psi, no more. The one common problem I have run into with the symtoms you describe is a float that is set too high or a needle and seat that has dirt in it as others have suggested here. To check the float, run the engine (if possible) pull the sight plug off of the bowl, the fuel level should be just at the bottom edge of the sight hole. If it is pouring out uncontrolably, shut the engine off and pull the needle and seat out of the bowl by unscrewing the top of the assembley on top of the bowl fuel inlet. You don't have to pull the whole bowl off of the metering block possibly wasting a gasket and a bowl full of fuel. Look for dirt, even the slightest bit of it will screw thing up in a major way. If clean, screw it back in, adjust it to get a static level (approx) and fire the engine. Recheck the sight plug method and raise/lower as nessassary. __________________ 71 short/fleet ECE 4/6 drop, LQ4/700r4/3.42 gears 70 SS396 Chevelle 427/200-4R/3.73posi 61 Lincoln Continental, black on black Son you are going to drive me to drinkin if you don't stop drivin that hot rod lincoln

10-08-2002, 06:40 PM	#4
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	On your o-1850 600, have you had bowls off?......check to see if the bouyancy spring has bounced out that goes under the float......that will cause a big flood over problem. good luck.....crazy longhorn

10-09-2002, 06:22 AM	#6
the-wreck Registered User Join Date: Sep 2001 Location: LI New York Posts: 159	Thanks guys. I will check the above mentioned items. I was thinking I may have too much fule pressure, howerver, I have used lots of Holleys over time and never had one fllod over like this due to fp. Then again it could happen.



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