Second brand new Holley carb flooding?

-
G

Gwywnc

Well-Known Member
Joined
Sep 15, 2015
Messages
58
Reaction score
5
Location
Cherokee nc
I have a duster with a 440 with a automatic and the second brand new carb is flooding just like the first one. It doesn't happen constantly and there is no rhyme or reason why or when it does it. The gas comes shooting up from a tube above the first side of the carb. Any ideas?
 
Do you have fuel filters. They should keep the dirt out of the needle and seat.

Or the float level is too high...
 
alot of time taking the handle of a screw driver and tapping it on the needle seat will knock any junk out of it...or unjamming a stuck needle and seat from bouncing around while being shipped
 
Check fuel level....
My quick fuel was a lil high and wud flood out on a steep driveway
Lowered fuellevel a lil, runs perfect!
 
d55dave said:
Or an electric fuel pump putting out too.much pressure, blowing the needles off their seats.
Click to expand...

I would think along the same lines.......at least it's something other than the carburetor since two have exhibited the same problem.
 
I bet this carb had **** in it from the get go.....Ya might want to take it apart and check it...
 
d55dave said:
Or an electric fuel pump putting out too.much pressure, blowing the needles off their seats.
Click to expand...


Yes, but if it was an electric fuel pump with too much pressure, it should happen all the time, not intermittantly...

Most likely something before the carb causing the issue letting dirt in the needle and seat.
 
A good needle and seat will hold up to 11 psi before it blows open from too much pressure. I had to go through several before I found a nicely matched set that lasts a long time. Three carbs = three times the headache when they aren't right. Check your fuel system for contamination, run several quality filters and make sure you have less than 6 psi MAX for street use.

I run 5.5 lbs on the street, but at significant volume. My new system took a while to get small bits of needle and seat disrupting contaminants out of it. Then I went through about 7 needle and seat sets until I found good ones. It's a process of elimination and persistence.
 
krazykuda said:
Yes, but if it was an electric fuel pump with too much pressure, it should happen all the time, not intermittantly...

Most likely something before the carb causing the issue letting dirt in the needle and seat.
Click to expand...

Not necessarily. If the fuel pump is putting out a pressure that's close to the upper limit for the needle and seat, then the needle and seat might work sometimes and only get blown off occasionally when the fuel pressure spikes up a little or conditions in the carb create an issue. That would appear to be random/intermittent.

What is the fuel pressure?
 
Yup. It's always better to make dang SURE your fuel pressure is right before you dig into it. Might be all it is.
 
Hi thanks for the replays. This is the third new carb. The first new carb was a 670 Holley street avenger. It worked great and never flooded. The problem was that it stumbled at take off and I couldn't get it to stop so I sent it back and got the 750 double pump. Both the 750s that have flooded seem to have started it after letting off the gas and the motor winding down. The gas is coming out of the front lil tube that sticks up. I adjusted the float level and looked at the needle of the first 750 and it didn't help. The only reason I went with Holley is that say these things are tested before shipped and ready to bolt on at go. If I can't get get figured out I will never buy another Holley.
 
And I don't know if this will help but the first carb was on the car a week before it started acting up and the next carb was on for a few hours and ran fine before it started messing up.
 
Sounds like you need a fuel pressure regulator.
If you already have one perhaps you need a new pressure gage, could be reading wrong.
 
Trash & debri is the most common problem for Holley flooding.
It doesn't take much.
 
dwire67 said:
I agree
Too much fuel pressure or dirt in the needle & seat
Click to expand...

mikedevore said:
Trash & debri is the most common problem for Holley flooding.
It doesn't take much.
Click to expand...

Doesn't matter the brand of carb, the above issues will screw up any carb, not just Holley..

Breadburner said:
I bet this carb had **** in it from the get go.....Ya might want to take it apart and check it...
Click to expand...

If it's got chit in it, it's awful hard for it to move upstream to the needle and seat..
 
inertia said:
Doesn't matter the brand of carb, the above issues will screw up any carb, not just Holley..



If it's got chit in it, it's awful hard for it to move upstream to the needle and seat..
Click to expand...

I think it has some shavings or something in it from the factory.....
 
dwire67 said:
I agree
Too much fuel pressure or dirt in the needle & seat
Click to expand...

It may well not be the issue. BUT, it makes no sense to proceed tearing stuff down without knowing WHAT the fuel pressure is.

So far, the OP seems not to know. That would just be number 1 on my list for diagnostic procedures. To make sure I had adequate (and not too much) fuel pressure all through the RPM spectrum. Once ruled out, then you know that whole issue is a non issue.
 
Gwywnc said:
Hi thanks for the replays. This is the third new carb. The first new carb was a 670 Holley street avenger. It worked great and never flooded. The problem was that it stumbled at take off and I couldn't get it to stop so I sent it back and got the 750 double pump. Both the 750s that have flooded seem to have started it after letting off the gas and the motor winding down. The gas is coming out of the front lil tube that sticks up. I adjusted the float level and looked at the needle of the first 750 and it didn't help. The only reason I went with Holley is that say these things are tested before shipped and ready to bolt on at go. If I can't get get figured out I will never buy another Holley.
Click to expand...

Could have just put a larger squirter in the first carb and adjusted your accelerator pump to eliminate the stumble. Reason it was doing that was because your motor was leaning out between the idle circuit and the main jetting taking over...

If you are doing any drag racing you might want connect the primary bowl vent tube and the secondary vent tube with a piece of rubber hose with an oval cut out of the top of the arch. Prevents fuel from sloshing out of the primary vent into the carburetor when the car launches.

After you get your problems ironed out that is...

Probable causes:
1.) Contamination in fuel system
2.) Float level is too high

3.) Fuel pressure is too high - kinda wonder if its this considering your first one didn't puke fuel out of the vent... Still a possibility, but need to know what pump / psi you have

Give us some more information so we can better assist:
Fuel Pump - part number
Filter - what is it and where is it located
Fuel pressure - if you have a gauge installed?
Regulator
 
You must log in or register to reply here.
-

Back
Top