Fuel flooding out of bowl vent tubes (Holley 4180)

[graphicdesigner80]

**UPDATE**

The only mechanical fuel pump found that put out less than 12 psi is the Edelbrock 1725 - https://www.summitracing.com/parts/edl-1725 ... For $140 it should come with a free gas card!

This was a last-ditch before going with a regulator. It's advertised to produce 6 psi. My gauge shows almost 8 psi. Was disappointed at the higher number, but carb seems ok and is no longer flooding out. Readjusted the floats and all seems well - for now. This pump has no return provision, so the return line is plugged and tucked out of the way.

It's really disappointing that out of all the fuel pumps out there, nobody seems to care that they're not functioning correctly. I even contacted Scott Drake to inquire about their pump. Response was "it's just an airtex pump..." There has to be more people out there experiencing issues. I tried about 12 different pumps and pressures varied wildly between 12-17 psi! Even the early Windsor pumps with no return provision still put out too much pressure. Wish there was a way to open them and change/cut the spring. Talk about a hassle!

If anyone happens to come across a good mechanical pump for less money that puts out less than 8 psi, I'm all ears!

Hopefully this will help someone out in the future.


**Original Post**
It's been a long time coming... here we go!

After a lot of searching and finding just a single post with a similar issue (but different fuel pump) I'm taking a guess, but wanted some input.

'84 GT convertible, 5 liter, 5 speed. Car was bought as a roller with no drive-train. Installed a roller motor, speed-density cam, Edelbrock performer intake, everything else stock. Pieced it together and got it to fire up.

I bought the recommended Carter fuel pump (M60253) from rock auto. The car starts right up but within 3-5 seconds, I get LOTS of fuel flowing out of the top of the bowl vent tubes. Starts with the front tube, then shortly the rear tube flows as well. No vent plumbing hooked up yet, as I'm just trying to get it running and dialed in. Verified that the needle/seat & floats are not sticking.

Tested with two carburetors (both 4180's) with the same results.

Has anyone had an issue with these Carter pumps putting out too much pressure? That's the only conclusion I can reach. It's just pushing open the needle and seat and flooding out. I do not have a gauge or regulator since this was supposed to be OEM for what these cars are supposed to have new.

The return line is hooked up and everything is clear... verified by blowing through lines and having an assistant listen at the tank with the cap off. I replaced the rubber sections of fuel line (using fuel-grade rubber hose) just to make sure nothing was collapsing. Pressure line from pump to carb is steel with no rubber.

I originally had a cheap parts-house fuel pump that was dead on arrival... never pumped at all, so I read up on here and the Carter M60253 was recommended, so I went with it. Any other suggestions on different pumps or anything else I should check?

**EDIT**
The listing on rockauto's site has this pump's max pressure listed at 8psi. I'm guessing that's at high rpm and not idle. Most parts-house pumps are listed in the 6.5 psi range. Can anyone clear that up for me?
Thanks!