Carb question

bigdaddy999 · 08-28-2005, 10:43 AM

i have a holley 750 4bbl double pumper on my stang. I recently noticed that only two of the 4 bbl were working. I was wondering if anyone knows why this owuld happen, and if ican take the carb apart and fix this, or is it just time to get a new one? Thanks for the help

Ieatcamaros · 08-28-2005, 11:11 AM

Is it a vacuum secondaries? Either your vacuum line is unplugged or busted somewhere or the diaphram is busted. If its mechanical secondaries, you need to look at the linkage. How old is this carburetor?

BLACK85GT · 08-28-2005, 11:52 AM

are you looking at it in Idle or Wide open throttle. The secondaries only kick on at full throttle.

Gearhead999 · 08-28-2005, 03:37 PM

How do you know the other two aren't working??

Ieatcamaros · 08-28-2005, 08:48 PM

Quote:

Originally Posted by Gearhead999

How do you know the other two aren't working??

I wondered the same thing.

82 GT · 08-28-2005, 09:20 PM

Quote:

Originally Posted by Ieatcamaros

Is it a vacuum secondaries?

If it's a double pumper then it can't be vacuum secondary.

bigdaddy999 · 08-29-2005, 09:05 PM

i ntoiced it wasnt working when i was under the hood using the throttle to give it gas, and the two wouldnt open no matter how much gas i gave it or how long i gave it gas.

82 GT · 08-29-2005, 11:39 PM

Are you sure it's a double pumper because it sounds as if you have vacuum secondaries in which case, you won't see them open because the engine isn't under load when it's out of gear.
The secondaries only open as the demand for fuel increases if, indeed, you do have vacuum secondaries.
If you have machanical secondaries and they aren't opening then I would say you have a linkage problem.
What is the model # of the carb. you're running? This will verify what kind of secondaries you actually have.

PKRWUD · 08-30-2005, 05:19 PM

Sounds like you have a 3310 to me. Try what 82 GT suggested, and post the List #, found on the airhorn (choke tower). If it's 3310, then you've got a vacuum secondary 750, and it's operating normally.

08-28-2005, 10:43 AM	#1
bigdaddy999 Registered Member Join Date: Aug 2005 Posts: 34	Carb question i have a holley 750 4bbl double pumper on my stang. I recently noticed that only two of the 4 bbl were working. I was wondering if anyone knows why this owuld happen, and if ican take the carb apart and fix this, or is it just time to get a new one? Thanks for the help

08-28-2005, 11:11 AM	#2
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: Carb question Is it a vacuum secondaries? Either your vacuum line is unplugged or busted somewhere or the diaphram is busted. If its mechanical secondaries, you need to look at the linkage. How old is this carburetor? __________________ The sig says it all.

08-28-2005, 11:52 AM	#3
BLACK85GT Registered Member Join Date: May 2002 Location: Tampa,FLORIDA Posts: 340	Re: Carb question are you looking at it in Idle or Wide open throttle. The secondaries only kick on at full throttle. __________________ 5.0, Holley heads, 1.7 Scorp Rockers, Stealth intake, Holley 600 carb, Holley Mech. Fuel pump, MSD 6Digital, MSD distributor, Hotchkis upper/lower rear control arms, FMS B Springs, 3:73 (8.8) rear. Production # 9,377

08-28-2005, 03:37 PM	#4
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Re: Carb question How do you know the other two aren't working?? __________________ "Support our Troops" Dave 1968 Cougar 2004 Thunderbird 2007 F150 Harley-Davidson, SuperCrew 1986 LTD 1997 Ranger 1992 Honda Civic

08-29-2005, 09:05 PM	#7
bigdaddy999 Registered Member Join Date: Aug 2005 Posts: 34	Re: Carb question i ntoiced it wasnt working when i was under the hood using the throttle to give it gas, and the two wouldnt open no matter how much gas i gave it or how long i gave it gas.

08-29-2005, 11:39 PM	#8
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	Re: Carb question Are you sure it's a double pumper because it sounds as if you have vacuum secondaries in which case, you won't see them open because the engine isn't under load when it's out of gear. The secondaries only open as the demand for fuel increases if, indeed, you do have vacuum secondaries. If you have machanical secondaries and they aren't opening then I would say you have a linkage problem. What is the model # of the carb. you're running? This will verify what kind of secondaries you actually have. __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

08-30-2005, 05:19 PM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Re: Carb question Sounds like you have a 3310 to me. Try what 82 GT suggested, and post the List #, found on the airhorn (choke tower). If it's 3310, then you've got a vacuum secondary 750, and it's operating normally. __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

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