Too much fuel....

[steve73]

I am running a Holley street avenger carb on my new 302. I have an in tank 155 pump and am running a Mallory regulator with return line. This is not working as the carb is puking fuel and my 15 (max) psi guage goes crazy when I turn in the pump. Is there an easy fix using my existing setup or do I have to ditch the in tank pump and go mechanical.?

If I have to switch pumps, can I just unplug the in tank one and leave it in there or do I need to remove the whole thing? Thanks

Btw the reason I went in tank is because I was going to run EFI then changed my mind. Thx

[riptide motorsport]

Have you adjusted the regulator? turning the allen screw out I believe lowers the pressure, run 4-6 lbs...Steve

[steve73]

Yes tried that with no luck, in fact even a half turn in of the adj screw makes fuel flood out of the carb. There is definitely too much fuel going in the regulator and the reg can't seem to handle it. I think I may have to change pumps so maybe i will just go back to a stock in tank pump. If that doesn't solve it, then I will have to switch over to a mechanical pump unless anyone has any other suggestions.

I have checked for blockages in the return line and it is clean. I have read that I may need a bigger return line, but the stock return fitting at the top of the tank is small so I am not sure that a bigger ID line is the answer?.

[Ray]

I also have the Street Avenger carb (570) and am using a Holley Blue fuel pump and pressure regulator. The carb isn't designed for more than 9psi of fuel pressure and I'm running about 5.5. You need to turn the fuel pressure WAY down or you will continue to have problems.

Ray

PS: From the pdf files at Holley.com "The recommended fuel pressure is between 5-7 psi."

[Norm B]

Is your return line the same size as your supply? I modded the return into the tank so both lines were the same size.

Norm

[Gordon Levy]

You are trying to run a EFI 50psi pump with a 7psi carb. There is only 1 regulator out there that will allow you to regulate the fuel pressure down to 7 psi from 50 psi and it's by Aeromotive.
You would be better off putting a carb pickup in the tank and use a proper electric fuel pump.

[steve73]

Thanks for the replies guys. It seems apparent that my current setup will not work and I will have to ditch my in tank pump and likely go with the Holley Blue. So my next question is what do I need to do to modify the current in tank pump setup in order to use a standard pump? If I just disconnect the in-tank, will the Holley still pull gas through it or so I need to remove it altogether and put something else in there. Thanks guys.

[Ray]

... what do I need to do to modify the current in tank pump setup in order to use a standard pump? If I just disconnect the in-tank, will the Holley still pull gas through it or so I need to remove it altogether and put something else in there. Thanks guys.

I pulled the in-tank pump from the cage and attached a copper pipe to the "S" shaped rubber tube at the top of the OEM fuel pump cage. At the bottom of the copper tube I put a sock filter so that I have a pre-pump filter.

Ray

[steve73]

Thanks Ray, I will give it a shot.

[steve73]

Well you will love this.... Pulled out the in tank pump to look at making the modifications above and guess what... The return nozzle still had a cap on it!! So, after fixing my careless error of a year at when I installed it, I am now down to about 10 psi. This is still too much but at least not the 50 that was there before. Still have to cut it down to 4 or 5 but a bigger return line may solve this one. Thanks to all.

[riptide motorsport]

You will get it solved, that regulator will handle the job........just adjust it down.

[steve73]

A few more questions for the group (many thanks in advance):

After unplugging my return line as above I still could not get down below 10 psi. I decide to go with the Holley blue pump as suggested by Ray, which arrived today...

So.. If I modify the old in tank casing by replacing the in tank pump with some tubing, will this work as a fuel pick up or is there a better solution?

I have a Ron Francis wiring kit, should I modify the old plug that powered the in tank pump and use it for the new Holley, or should I run a separate wiring setup just for the new pump?

Instructions say that the pump should be mounted below the lowest point of the tank - is this critical? Fuel line would still be running from the top of the tank down to the pump unless I am totally confused..

Return line or not? If so is the existing FfR supplied line sufficient or do I need to go bigger?

Thanks again guys.

[CJBergquist]

This is what I used.

http://www.summitracing.com/parts/GRN-GM-TI7998/

[McLovin]

If you are going to go with a return and you're willing to consider a soft line, I picked up a Morosso return setup from Forte's that worked wonders. Instead of having to modify the pickup, it's a tube that fits in line with the fuel filler hose - I want to say it's 3/8". You plug it in where you want on the fuel line, run your return line to the nipple...and you're done. My problem was very similar to yours, between opening up the regulator almost all the way and the return, my problem went away all together.

[steve73]

Thanks guys. I will take your advice and report back. Cheers