Fuel Pump Questions

Hello All,
Seems I have too much fuel presure. Blows right past the little check valve in the carb(weber). I tried switching to a Holly. Same thing, fuel just bubbles right out the top of the carb. Went back to the weber. This time with a regulator. It's better. I can get it to run at least. Only it's either starving out or it still bubbles out the top. So,...
My question is, Are there different fuel pumps for a carby motor verses an EFI motor. The pump I have has a return on it. I ran a line back to the tank. I'm thinking maybe I used too small of a return line and it may be causing an increased presure in the feed. Anyone have any experience with these things. I've been screwing around with this thing for far too long. I wanna drive my car. Please help!. Thanks a ton,
Dave

What regulator do you have? A bypass type is best by a long shot. The Holley style tends to get idle creep.

EFI motors had a remote pump. Not really sure beyond those surmises, without seeing it.

Give up on the carb and return line fuel pump!.If you change too much of the carb system, your better off going to a US one.

Trying to be peacefull about it, I guess I find it ironic that just running the stock Aussie 83 to 93 X-flow fuel return line system should be such a problem. Ford US did it in all there 5.0, 5.8 4-bbl H.O engines from 83 to 88.

From my anaylsis of the six or seven people here with x-flow projects, every one hates the return line idea with a passion!.

Democracy rules!

The return line has to be huge, and it has to be at the same level as the fuel tank, not above it. The Weber return line must be lined up as per stock.

The old Does10's method of running the return line into the tank breather is a bad one, and I was wrong to ever suggest it as an option.

I think your better off using a US fuel pump, and hooking up a Holley.

I've been doing a lot of research, and I'm convinced that ditching it is the best option. The US roads may have broken joints in the cement, but asside from a few craters, they are not rough and geometrically tight like some Aussie and most Kiwi roads, nor is hot fuel handling. All 1-bbl Falcons and Cortinas before 1982 suffered from chronic fuel surge in corners. The return line Weber is basically a Fiat carb, and has no problem with fuel surge even in a Fait 132, which leans up to 8 degrees thru hard corners.

The Weber hates any more than 3.5 psi, has a great float bowl, and runs a full evaporative emissions and relay system even in the non EGR NZ emmision spec.

If everything is kept stock, the Weber ADM 34 is a better carb than any stock Holley, but when a carb X-flow goes into a US Ford, then your better off junking the fuel system and using the local bits. One thing I've learned is that the US stuff is better because you can get parts quickly and tune it properly.

The ideal jet and power valve sizes for a stock 4.1 with the EFI 264 degree cam and the stock single outlet exhast are likely to be :-

For the 7448 350
65 main jet
6.5 power valve

For the 4412 500
69 main jet
6.5 power valve

While I didn't want to run the return at first, I did and it wasn't hard. I thought it might be a good idea thinking maybe fuel injection in the future. I used the smaller line on the return because the factory nipple on the pump was smaller than the feed line. I never thought it would fight me to the bitter end. Had I known a US fuel pump was a viable option, I would have done it months ago. You just wouldn't believe what I've gone through trying to make a go at it. I'm at wits end. I'm gonna go buy a new fuel pump now. Swap out the manifold and carby, again...Augh!!!
Oh well, the good news is, in trying to resolve this issue, I built up a really nice holley for it. Thanks for the advise guys, again. I'll let ya'll know how it goes.
Thanks Dave

are you using a carby fuel pump on it ??

they are about 2-5 psi

if your using the efi pump then o course it'll blow past the valve as those pumps pump a stupid amount of psi to hold fuel pressure @ the fuel rail.

i'd be looking @ what psi youd pump is. and if you can get a regulator on your line to stop it pumping tooo much if this is the issue.

This should help. The 73-77 Capri/75-78 Mustang II 5200 Holley Weber adaptor.

Slap it on your existing ADM intake manifold, and add a 3/16 alloy plate to mate it the the 2300 Holley carb.

100% American content!



There is another option too.

On my old XE Falcon, I just bought a 2300 Holley spacer, added some thicker aluminum spacers, and bolted the Holley on.



Hope this helps. Excuse the photo edit, not everyone liked it when it was showing an Impco LPG carb on the Hlley throttle body, so I edited it out.

why dont you throw the pump and put an eairly fuel pump on it,one that doesnt have the return line?i have the xe/xf twin barrel webber on my car and use the eairly glass top fuel pump and my car runs perfect,i use it everyday.

Thanks for the input guys. I was thinking I may have an EFI pump(if there is such a thing). I did go buy a new pump. I thought I read that I could swap out the arm. I haven't compared them though. Has anyone done this?
Dave

your local car parts store should have one

i bought mine as a inline fuel pump.. ran the hose coming out of my tank into it.. and another hose out the otherside and back into the line to the carby.
then ran some power to it... i had 6m of heavy duty speaker wire.. that does the trick ran from my jumble of wires to the fuel pump in the boot.

and voilah

electric fuel pump suited for a carby..
mine is 2-6psi.. and runs my 250 xflow with no troubles
put foot down and opens up like a horsepower hero with no troubles due to the fuel supply

look out for one simular psi to the one i got and you should be on the track of a winner.
on the box it sez suited to 4/6 and v8 engines
so will work with a holley with no drama's also.

I did an ADM 34 to XD Alloy Head conversion, and using the stock XD pump, and return line blocked off.

Result? It caused massive leaking with the Weber carb.

Eventually, we shoved in an XE fuel tank with return line, no problems. You Aussie guys are just fortunate!


The Chev Luv (Isuzu 1586 cc engine) ran an electric pump, so did the Aussie Holden Gemini (same engine). Its a good item to use, runs at low pressure, although its wire-up is rather odd.

Stock EFI pumps yield anywhere from 45 to 55 pounds per square, and won't allow a Weber to live, even with a couple of pressure regulators.

How do you guys put your photos in ?? I tried but could not so just put a link in ..

Danielson":250qz20n said:

How do you guys put your photos in ?? I tried but could not so just put a link in ..

Click to expand...

Use [ img ]http://www.your.image/location/imagename.jpg[ /img ] (without the spaces in the brackets)

Click on the Quote button their posts to see the code you need

The arm on the us fuel pump looks different. I think it is longer and straighter. I cant see how you would go about changing it. I am using an aussie fuel pump which appears to be stock for a carbie engine. There is no return line being used off it. There is a plug on one side which I guess is used for the return option????

Carquest sells an electric pump for like 50 bucks. Probably need to slap on a regulator with it but that may work.