Holley 4160 4bbl woes

fordtrucks4ever · Jun 25, 2007

Carb was in need of a rebuild since it sat for too many years. Leaking bowl gaskets, poor idle, the usual. After new kit installed the rear bowl will not keep from flooding. I adjusted float level all the way down and still pooring fuel in bowl. Off carb it checks out fine. Then I removed another rear bowl from a known working carb. Same thing. Pull the float screw and fuel is pooring out the back bowl Adjust it down till float is inoperative and still flooding. I changed to three different rear bowls, 4 floats, 3 new needle/seats, and stiffer float springs. Nothing changed. It will not quit flooding. Front bowl adjusted perfectly and works. Orings have been changed on new and used needles, and seating properly in bowl. I have adjusted it full range and nothing will keep rear bowl from overfilling. I have another carb I gave up on a few years ago when it did same thing. I remember another carb that had the rear completely blocked off. I replaced parts to get rear barrels usable and same problem again. Only on the rears. What gives. I hate Holley carbs since they all leak after sitting any length of time not being used. I have to be overlooking something simple, but dont know what else to do, except go drink some beer and start over......

wildbill · Jun 25, 2007

Look for a crack in the houseing around the needle. When you have it off try it with some air (4 to 5 lbs.) and work the float by hand. Good luck hard to find not beeing there.

Bill %)

;D

daddyg · Jun 25, 2007

I had the same problem on my 470 TA. I replaced the needle and seat that didn't seem to fix it so I changed out the secondary bowl tonight, seems to have fixed it.

bludorbronc · Jun 25, 2007

You didnt say where the gas was running out of, down the inside or out of the float level adjustment hole on top. I have seen when the float is set that the flat washer gasket on top or below the adjusting nut are gone or torn and lets gas run free.

fordtrucks4ever · Jun 25, 2007

Everything was replaced with new. And it is flowing out the float set hole. I adjusted it down until float bottomed out and still flowing. This same thing kept happening with other new and used working parts and bowls from different carbs. Needle/seats/orings were changed out along with floats and springs. Front works fine, just nothing is working on rear. Stock mechanical fuel pump thats been on for a few years. What I dont understand is why the front has no problems at all. Rear is nothing but flooding. The problem has to be right in front of my face, just cant see the trees because of the forest...

iwlbcnu · Jun 26, 2007

If it is flooding it has to be the needle and seat are not sealing. Apparently you are missing the same thing everytime. Or the float is getting hung when you install it.

ugly74 · Jun 26, 2007

huh...I'm stumped. ?:? I was going to suggest maybe a flooded float (full of fuel) but you changed that. goobers in the needle/seat? nope. I don't get it.
maybe you need an exorcist?

any chance you could take the bowl off and take some pics of it?

bushman · Jun 26, 2007

What fuel pump are you using?

Mikey · Jun 26, 2007

Good point, if you have too much fuel pump pressure, the needles won't seal.

Going from memory, Holley circulates fuel in the rear bowl somehow to keep it fresh. Without my book, I can't recall any details on how this is mechanized. Might research this.

Good luck!
Mike

Mikey · Jun 26, 2007

Also, you get large adjustments on the floats via bending the tab in contact with the needle....your static bowl-upside-down setting is good, right?

daddyg · Jun 26, 2007

daddyg said:
I had the same problem on my 470 TA. I replaced the needle and seat that didn't seem to fix it so I changed out the secondary bowl tonight, seems to have fixed it.

Correction.. Mine isn't totally fixed either. It started flooding on me again at lunch..

iwlbcnu · Jun 26, 2007

This weekend Eoth on here started asking me about his TA, it was cutting out on him. Later it would only run at throttle and blowing black smoke. I pulled the AC and it was dripping out the secondaries and the overflow tube. We tapped on the needles with no results. I pulled the seat which dropped the needle inside, don't remember a standard Holley doing that, I finally pulled the bowl and reseated the needle and he was fine. Either he picked up thrash which I found none, or now ya'll have me thinking it is a design problem.

broncnaz · Jun 26, 2007

Mikey said:
Good point, if you have too much fuel pump pressure, the needles won't seal.

Going from memory, Holley circulates fuel in the rear bowl somehow to keep it fresh. Without my book, I can't recall any details on how this is mechanized. Might research this.

Good luck!
Mike

Its just the rear idle circuit that uses fuel to help keep it fresh.

fordtrucks4ever
Check the secondary metering plate its either loose or you have the wrong gasket. When replacing the gaskets they have to match exactly or you'll get leaks.

fordtrucks4ever · Jun 28, 2007

It started running rich after I began driving the truck again. Same fuel pump for three years. Been sitting for the last couple of years without much use. Tanks are clean and gas is fresh. I did match gaskets, but will recheck everything again and again. This isnt the first carb its happened to. Just after so many times tearing apart everything, its just as easy to bolt on a new Edlebrock and throw the Holley in the scrap pile. Fuel is only comming thru the tube from front bowl. It can only pass thru needle/seat. They are new along with orings. Changed all internal parts with other known working parts and nothing changes. I have another carb from a few years ago doing the same thing. I gave up and just changed it out.

ugly74 · Jun 28, 2007

seriously, if you're just gonna toss it out, send it to me! I love collecting old crap that would otherwise hit the trash.

Bronco Paul · Jun 28, 2007

What's your fuel pressure at? A Holley can't take very much I think its no more than 5 psi otherwise the pressure will keep you needle open and the float will not be able to close it. Your pump should put out anywhere between 4 -7 psi...so just put a pressure regulator on your fuel line before the carb...had it happen once to me...Edelbrocks can usually handle the 7 psi. The front float worked fine because my Holley fed through the back bowl first and the vent was the path of lease resistance so it spewed from there first.

kirkallen143 · Jun 29, 2007

fordtrucks4ever said:
Fuel is only comming thru the tube from front bowl. It can only pass thru needle/seat. They are new along with orings. Changed all internal parts with other known working parts and nothing changes. I have another carb from a few years ago doing the same thing. I gave up and just changed it out.

The only reason your fuel is coming out of the vent is that your float is stuck down (or something is holding it down, jet extensions and/or float spring on backwards maybe?) or you have a bad needle/seat. Is your float floating, no holes or pin leaks in the thing, shake it, if you hear fuel sloshing it's bad. You said that you had the float level set correctly, just trickling from the bottom of the site plug, right? And, you did it while the engine is running, correct?
Had the same thing happen to me, on the needle/seat it was bad, looked up in it and the seat had some brass missing allowing it to leak.
Seriously, take the bowl off and blow into the fuel inlet while holding the float up and see if any air get bypassed. If it is OK, then check for trash (it doesn't take much) in needle/seat or if your float spring is on correctly.
Just some thoughts. Good luck.

Kirk

Mikey · Jun 29, 2007

For one thing, and this can't be over-emphasized: USE ONLY HOLLEY PARTS for your rebuild!!!

With that said, with the new fangled ethonal creeping into the gas, the rubber o-ring on the needle/seat assembly will dry out pretty quick. The gas will bypass your needle and flood out through the vent. I just grabbed a big box of assorted o-rings and change the o-ring(s) out when they start messing up. Over the years, those o-rings fail A LOT!!! Also, the ones on the balance tube. Good news is they are cheap and easy to change...even on the trail.

Good Luck!!!!
Mikey

DonsBolt · Jun 30, 2007

I have been having the same problem with my rear bowl on my 670 TA

I just replaced the rear needle and seat, so far so good

I will let you know if it still is working in a few days, or weeks.

Holley 4160 4bbl woes

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