Holley 94 driving me nuts.

Guys,
If any of you have ever ran into this problem before and solved it...I'd really appreciate some input. I've been fighting with 2 Holley 94 carbs for the better part of a week.
Here's the quick run down:
Ford Flathead 1948 model 59 motor, stock dual point distributor, vacuum advance checked and working properly on rebuilt unit.
2 Holley 94 carbs, model 59s on an Offy intake centering carbs over the ports, .051 jets, 4.5 powervalves modified for 94s, both carbs fresh with new throttle plates and rods and roto-disc type needle and seats.
Carbs have been removed and power valves checked for leaks. Nothing leaking.
Electric fuel pump(4-7lb), new Holley pressure regulator and gauge running 2 lbs pressure.
Had an overflow problem from center nozzle bars while running and directly after shut off, so I dropped the floats to 1 11/32". This solved the problem and the car ran good. Threw in a new set of plugs and took her out for a good run (15 miles), started missing and running rich after about 10 miles, limped home and noticed the carbs back to running over from center nozzle bars. Still have 2 lbs fuel pressure. I've never had carbs fight me like this...any help is much appreciated.
Thanks,
Mike

 

Sounds as if fuel is boiling in bowl ,i'dput an insulator style spacer under carb either wood or phenolic

 

sounds like the fuel inlet valve,
the one above the float,
is sticking.

Do you have a fuel filter?
Did you replace the whole screw on valve assembly?
Is it leaking out of both carbs or just one?
TP

 

Running a new fuel filter and it is both carbs...the front one more than the rear, but both carbs are running over.

 

If it were mine,I'd put the regular needle and seats back in it!!!!!!

 

wbrw32....you run into probs with the roto discs before? it is acting like a bad needle and seat aint it...

 

One thing no one has mentioned is a float sinking. Some little pin holes take a long time to fill the float. if you change the needle and seat with no results or while changing it take the float and give it a shake. Believe me, you'll know if it's got fluid in it.

 

I'm just an "old fart"hotrodder and don't believe in some of the "new fangled shit".Kinda like triple fire spark plugs.To answer your question,yes it acting like the needle and seats.

 

Very true,but chances of the floats in BOTH carbs having a pinhole are slim to none.One Maybe but not both.

 

I agree it 's most likely the fuel inlet or the float itself, but you might also want to confirm that your fuel pressure is actually what you think it is. If it's possible with your intake, I'd go to a stock mechanical fuel pump.

Rich

 

have had dirt in one jet and it did the same thing.

 

make sure your fuel presure gauge is acurate i had the same problem and my cheap mr gasket fuel pressure gauge was off buy 1.5 lbs,

 

1) Make sure you are not using the new plastic floats. The alcohol in fuel eats them up. Use only brass floats.

2) .051 jets might be a tad big, but solve your other problems first.

3) Set your float levels by "bench testing" the carbs with the tops off, using the electric fuel pump and fuel pressure regulator that will be run on the car. This would be an excellent time to observe if the fuel inlet needles and seats are actually performing correctly.

4) The newer needles with viton seats work better than the old check ball type fuel inlets, but make sure the tabs on the floats aren't hitting the carb body before they can fully seat the needle.

Also, the leather type accelerator pumps seem to work better then the newer ones do, if you happen to have it apart.

Flathead Jack has any parts you might need, some of the vendors here on the H.A.M.B. may as well.

Good luck.

 

Could it be a vacuum/compression issue?

 

It doesn't have to be both floats to react as it is. One will more than give the symptoms he suggests.

 

thanks for all the feedback...it certainly gives me some where to start again...I do know this for sure though, it is both carbs because I yanked the air cleaners and physically looked down them and see the fuel running out of the center nozzles

 

stop and go....didnt step on it too hard

 

Still have to check to make sure floats are same, dont know vac at idle. Big cam?...Isky Jr "3/4" dont recall exact spec at this moment...but maybe you are familiar with this typrical cam upgrade. Standard shift.
Let me ask this question...what would happen if I plugged one or both the power valves?

 

I've learned the hard way that taking one carb off and blocking that intake port works best. Get it to run right on THAT carb, then replace it with the other one. Get it to run right on that one too. Then put them both on and work with the throttle linkage and idle circuits to tweak them. It takes a little time to get it right but it works for me.