have a holley double pumper on my 48 chevy installed an electric fuel pump when i turn the car on its fine for about 3 seconds and then fuel starts flooding from the top of the carb from the 2 vents.do i need a fuel pressure regulator or is there a problem with the carb.thanks
i usually deal with edelbrocks and carters the holley was on my car when i got friday low on funds so it will be awhile till i get another carb
There are no "Holley problems", only users who don't know what they're doing. It sounds to me like you indeed need a regulator. What psi is the pump rated for?
the brass sight plugs on the float bowls.. do them one at a time.. pull plug, adjust needle & seat until fuel just barely trickles when you bump the car with your weight.. thats how i do it anyways. rinse and repeat for the back bowl
Or perhaps those who have bought into the Holly Hype, and were forced to learn how to fix "Holly problems" in order to keep their rides on the road. SAFU
also to add if you've never messed with a holley before go get a holley tuning book..at the autozone around $15
Yes ,i would run one even if the pump is preset.The regulator is only about $30.00 .I run one along with a pressure gauge on mine.My Demon is set at 7 1/2 psi ,at 8 psi it tries to overpower the needle / seat assemblies and flood.This is on a race application.I would run more like 5 or 6 psi on a street car.Holley's and Demon's are great carbs ,if you know how to adjust them .More used on race car than all the others combined ...
>>>>YES! You need a pressure regulater AND a guage ,,Holley standard needle & seats won't accept anything more than 5 psi ,,,set the regululater at 4 1/2 psi and your problem will be solved ,,easy to do with an allen wrench without the motor running ,,just turn the key on & let the electric pump work ,,and adjust the regulater ,, Been rumnin' Holleys for 40 years ,,have a pair of Blower Specific 600's on my 6;71 blown SB Chevy ,,
You probobly have something in the needle valve that is preventing it from closing. I would remove the bowls and clean them, remove the needle and claen it and the seat. Use carb cleaner. Replace or add a filter. You may have a worn needle and/or seat. The float level may be too high, that should be checked. Then if it is still happening invest in a regulator or replace the pump. Might try a fuel pressure gauge to check pressure so you know for sure what you have. Holleys were used as OEM carbs for decades without regulators, but sometimes the internal regulator on a FP may fail. It happened to me once, thirty years after my first Holley with many Holleys in between. So never say never. BTW, AFBs are far more sensitive to FP pressure. And they have the famous self-emptying accell pump well. Check the website below for good Holley tuning tips. http://www.bob2000.com/carb.htm
YEP get that fuel press down to less than 5 psi solves a lot of problems a lot of electric fuel pumps creep the pressure up and it causes problems
>>>>,I'm running a Holley "Blue" electric fuel pump ,,it puts out 8 to 9 psi ,,so i have my regulater set at 4 1/2 psi ,,a fuel pressure regulator won't effect fuel volumn ,,just pressure ,,you'll still get all the gas you need at wide open throttle ,, also ,,,like the guys have suggested ,,,check the float setting as described above ,, if you decide to run a stock type mechanical fuel pump,,,you won't need the regulator ,,stock mechanical fuel pumps don't put out more than 5 psi ,,that's why stock factory OEM Holley carb installs didn't need a regulator ,,
thanks guys.ran the id number for my holley and its a 3310-2 750..this is to much carb anyone want to trade me for a smaller carb?
From Holley tech dept; How do I adjust the fuel level on my carburetor? ANSWER Setting the fuel level should be the first thing you do before attempting to make any further adjustments.The float level should put the fuel level just below the bottom of sight plug hole. You will make the adjustment with the vehicle on a level surface and the engine idling. You will first remove the sight plug, then to make your adjustment you will need to loosen the lock screw on the needle and seat. This will allow you to turn the adjusting nut to raise or lower the float level. Each hex flat on the nut will change the float level approximatly 1/32". When you have the fuel level just below sight plug hole you will then tighten the lock screw and reinstall the sight hole plug. Make sure you have a shop towel handy in case you have any fuel leaks from the Sight plug or needle and seat adjusting nut. In case it's not obvious, the lock screw and adjusting hex they talk about are on the top of each float bowl. The hex actually screws the seat for the needle valve up or down in the bowl to change float level. 40hemi on your car I would try setting the float levels first because it's quick and easy, especially with an electric pump because you can do it with the engine shut off. If you can shut your pump off, run the fuel low in the carb. (or crack one lower bowl mounting screw on each bowl to drain some). Then pull the sight plugs, crack the seat lock screws and turn the hex nuts clockwise to lower the seats. Then switch your pump on and set the float levels. Reinstall the sight plugs and you're done. I should mention that if this car had sat for a long time, it's not unusual for the floats and needles to stick open on start up. A sharp rap on the bowl with a plastic hammer or large screwdriver handle while fuel is flowing usually does the trick.
At 4-7 psi, you should be fine without a regulator, but for the price, it's hard to justify not adding one. 58custom gave very good advice above, follow it and you'll be fine. It sounds to me like your floats need to be set, or are just stuck.
I've always used holley double pumpers on my race cars and now on my street rod. I have a holley red electric pump, no regulator, fuel pressure is 6 to 6 and a half, on a holley 650 - no trouble at all.
>>>>>,Using Holley Hi-Perf "Viton" needle n seats allows for more fuel pressure w' out a regulator ,,less than $10 bucks each from Speedway ,, what size motor are you running ?? has it ever back fired thru the carb ??? if so ,you might have blown the power valve ,,which will cause the carb to flood out ,,
like most said check float level and they don't like to sit for long periods(months) or the needle won't seat properly adjust as recommended. I have run 9psi on gas 15psi on methanol with different needle and seats easy carb to adjust
40hemi, your 3310-2 is not a double pumper (mechanical secondaries)as orginally stated but rather a dual inlet vacuum secondaries 750cfm carb and that is probably good news. It may be a little larger than ideal for a mild 350 that won't see past 6000rpm but the vacuum secondaries will let you get away with it. If your 350 is a hotter build with cam timing for the 7500rpm range and the car is geared accordingly then I'd say you're right where you want to be. That carb is quite similar in function to the 780cfm holley that GM used on the production 67-70 Z28's and the 70 LT1, to give you some idea of what kind of build would use it.
If the part number is 3310 that is not a double pumper even though it does have the big fuel bowl and external float adjustments. It is a vacumn secondary carb and a good street carb to boot. I first would try a regulator and pressure gauge as suggested. Once you get the pressure down to 5-6 psi then set the float levels as suggested here by removing the brass sight plugs on the side of the fuel bowls. All these adjustments can be done with the fuel pump on and the motor not running.
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