Adjusting float with electric fuel pump

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Joep

Joep

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Hey guys I have a 600 holley that I need to adjust the floats. I just can't seem I get it right. I can't figure out the best way to do it with an electric fuel pump. Every time I unscrew the soft plug gas comes pouring out. Does anyone know a trick adjust the float with an electric fuel pump? How long should I run the pump to pressurize the lines?
 
assuming they are externally adjustable...with a 5/8 wrench and flat tip screw driver ....with the pump off..turn or adjust the nut clock wise..this will push the float down...

now with the pump off...open the site plug...left the gas drain...or remove one of the lower bowl screw to drain the bowl...tighten up screws...with site plug open...turn on pump....slowly adjust nut CCW and let the fuel level rise....

part of your problem is once the fuel level is above the site plugs...even if you adjust the float down...you gotta get the higher fuel level down so you can see what the adjustment did....
 
What kind of electric fuel pump and are you running a fuel regulator? The pump will run continuously regardless of pressure. The regulator will control the fuel pressure going to the carb. Most of the time, 6psi is all that is needed and the float needle will shut the fuel off to the carb and open as needed.
 
It is a holley blue pump and it does have a pressure regulator but I haven't checked what the pressure is. So the fuel pump must be running to adjust the float? Wouldn't the pressure keep rising once the needle seats?
 
I cleaned the needle and seat even though it didn't look like it had any dirt on it and then then set the float so about two threads were showing on top but the float level is still too high. It idles fine but then once you give it a little throttle I can see that it drips from the boosters. Now I'm not sure if that's supposed to happen or not but it does.
 
Joep said:
I cleaned the needle and seat even though it didn't look like it had any dirt on it and then then set the float so about two threads were showing on top but the float level is still too high. It idles fine but then once you give it a little throttle I can see that it drips from the boosters. Now I'm not sure if that's supposed to happen or not but it does.
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if its dripping gas basically its flooding. the only fuel you should see is out of the squirters. either the pressure is too high, the floats are too high or there is crap between the needle and seat. fuel pressure is very important. too much and you can force gas past the needle, too low and you will run out of fuel. 5 - 6 is what you want.
 
Ok I guess next thing I'll do is test the fuel pressure. Should it rise and fall with engine speed or should it be a constant 5-6?
 
Joep said:
Ok I guess next thing I'll do is test the fuel pressure. Should it rise and fall with engine speed or should it be a constant 5-6?
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it may fluctuate a touch at the gauge but it will be a constant 5, 5 1/2 ,6 or whatever you have the regulator set at.
 
Take the floats off and bend the tang under the needle set, in order to have the needle set centered in the fuel bowl. The top of the floats need to be even with the bottom of the screw hole.
The adjustment is complete.
Don't forget to check the o rings on the needle sets or buy new sets, since the Vitton tip gets worn too.
Don't mess with the pre-set pressure regulator either.
A gauge on the engine will read 1-2 lb.s when warmed up, so don't get fooled.
 
and you need an adjustable float why? i have used Carter carbs for may years and it NEVER came to me that i needed an adjustable float.
 
carter carbs floats are adjustable by bending the tang.Holleys and carters are quite different.
 
yea i know carters are very different. thats why i like them. once its set it stays set.
 
Ok guys Im completely stumped. Now she won't even run! I adjust the fuel pressure down to 6 it was much higher, I cleaned the needle and seat with carb cleaner and compressed air and put it back in, ran the pump and set the float to where fuel was just starting to trickle out of the bottom of the sight plug. Fire it up and it runs awful and then dies out. Sometimes it will run ok for a few seconds then it lugs and dies out. It won't go above 500 RPMS. And after it quits running and I check the sight plug fuel comes out much faster than when i checked it with just the pump. It seems like it's still flooding but I can't tell at this point. It ran fine before any adjustments except for the flooding but now it won't even run!! Would it have any affect that I'm trying to start it int like 40 degree weather? I just can't figure it out
 
Tighten the idle air mixture screws all the way in. Then go 1.5 Turns out, exactly. Do the opposite on the other side. That should get you to a position where you can idle. If not, check your idle rpms. May simply need to raise the idle up.

After that, dial it in using a vacuum gauge.

- Christopher
 
Also, make sure that you are adjusting your floats with the motor running, buddy. But be careful!! With the flooding, if your floats are correct, I'd look into replacing the needle/seat. Sounds like they aren't sealing off.

- Christopher
 
I had the idle air mixture screws 1.5 turns out and it still wouldn't idle so i tried turning them out another half a turn and that sounded better but then it sputtered and died out again. I wouldn't think that would be a problem because it was idling fine just a couple of days ago, so i would think that they would still be ok. Would it be possible that the problem is linked to the batteries? It does seem a little bit colder than the days it was running better.
 
Shouldn't be a battery issue. Set the fuel pressure to 6 with the car running. Then adjust the floats. Does it rev up fine after you start it and just idle bad, or what?

- Christopher
 
I had issues with my secondary needle sticking open due to a small amount of trash. Have you cleaned both sides? Also, are you sure there are no vacuum leaks around where the carb bolts down?

- Christopher
 
You can't set the fuel pressure with just the pump running and the car not running. It will read higher than what it will be when you start it up. You could have just lowered the fuel pressure too low when you adjusted it, if the car was off.

- Christopher
 
It does run better once i bring the rpms up but then it kinda sputters and dies out and yesterday i was getting some pops out from the carb. But maybe that could be because it's flooding? I don't think there are any vacuum leaks although i did forget to put the plug back in the full manifold vacuum port yesterday before i started it but i did get the plug back on. And maybe the pressure is too low but wouldn't the car still run because the fuel bowls have plenty of fuel in them? I guess next thing Ill try is a new needle and seat. Thanks a lot Chris I really appreciate the help
 
If you are backfiring through the carb, I would look at double checking the timing on the motor.

- Christopher
 
Soi just got back in town and tried to fire her up but still no better. Will not idle. I gave it some gas and it ran better but it still sounded rough but i think that was just because it was cold, and as soon as i let off the gas it died. It seems to run ok when the throttle is open a little bit but once they shut it turns to ****. Will idle all the way down to about 50 rpms it seems and then quits. Not sure what it is and i didn't feel like fussing with it tonight
 
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