put a 140 gph pump on my car, external...i have a mallory afpr...the 80 dollar 3 port with the bypass port....

the fuel pressure now stays at a constant 9 psi....no matter where i adjust the afpr....yes its all hooked up right.

so....does the afpr tach out at 9 psi and i could be running 40 psi or some crazy s....er...nevermind

the AFPR worked fine when i had the stocker in tank pump on it.....wtf is up with this now?

 

Have the part number?

 

MAA-4309 mallory AFPR adjustable from 3-12 psi

the fuel pump came from ebay. from a place called dirt track thunder. www.dirttrackthunder.com

PROCOMP electric fuel pump 140 gph
mwm 128151

the letters in that might not be apart of the part #, im just reading everything off the box and posting it here.

thank you,
Sean

 

What size is the return line in relation to the feed line?

It could be possible that you are overfeeding your regulator. i.e. with the increased volume from the new pump, you are giving more fuel than the return line can handle.

 

eh, its the stock sized line...even if i went to 3/8s all the way to the tank ...it wont be 3/8 IN the tank....ya know....and even if i replace the line into the tank, on the assembly itll be at least 1 inch of stock line to connect to.....cut n splice, itll still have to force thru the smaller diameter line to go into the tank....causing more pressure

im not too sure whats causing this....im pretty suprised....i figured this would be a pretty dry cut install.....

i know all the lines are hooked up.....my setup goes

(Afpr)----(fuel pump)-----(stock type fuel filter)-----(tank)

i relocated the filter to right under the tank....i put the pump where the filter was.

im just not sure wtf is going on with this.....if it was overpowering the return line wouldnt the psi keep rising past 9 psi?

shouldnt the afpr limiting the amount of fuel anyways? the afpr will not regulate the pressure. guess it JUST regulates pressure and not actual fuel flow hence the name

any way to correct this? this pump is brand new, id hate to have to buy another one

i supose i could try running 3/8 line from the afpr to just before the tank assembly.....thats a LOT of rubber hose though, cause i sure as hell dont have the money for braided heheh

 

ok so, i unhooked the hose from the afpr return ....stuck it in a gas tank, hit the switch....nice Arch of fuel... runnin on 1 hour of sleep i left the port on the afpr wide open and stuck the return line going to the tank into the 2 gallon gas tank.

so....get my thoughts straight....get the CORRECT hose in the lil 2 gallon tank, hit the switch...afpr works when the bypass line is going into the 2 gal tank with a 3/8 hose.

so......im going to replace the line from the afpr and run it to where the tank assembly begins ...where the stock rubber line is.....and pray that it works.....im just wondering if this will even help since it goes back to the stock sized line right at the tank.

theres no way to replace ALL the metal line directly into the tank so this is as good as i can do...... --prays--

 

and yes i always respond to my topics when i have found a solution, i hate to leave things like this unanswered....in the hopes that one day someone runs into this problem and the search feature is useful for once.

 

Stek is describing exactly what I am thinking. It is also possible that the FPR itself cannot port that volume of fuel to the tank, having the same effect.

(Gotta watch out for some of those Michigan types. They're pretty sharp.)

And there IS a way to replace the steel line through the tank bung in the top of the tank, but you really don't want to do that if it isn't necessary. Dropping the tank is not a five-minute task.

 

well...like i said...i took the line off of the afpr (return line) and stuck it in a lil 2 gallon tank and hit the key....the afpr worked when i did that...so its the return line not being big enough.

ironic you say that vader.....i had to replace my friends in tank fuel pump, my gas tank sprung a leak from the bottom the DAY i got done with his....turned around....dropped MY tank.....couldnt get the hole fixed....pulled the tank out of my 86 parts car and it had a hole in the TOP of the tank from where some moron tried to ground an amp wire into the body....hit the gas tank....

so i patched the 86 tank because it had a perfect circle hole and since it was at the top, gravity wont work against it.....

THEN, when i pulled my stock fuel pump out to laugh at it....i pulled the strainer off and found 1000 pieces of small plastic stuck in the fuel pump screen from where i assume the old fuel pump impeller blew, shot into the strainer....fuel pump got replaced...strainer didnt.....thus how the crap got in the *new in tank pump*

just got my car back together....ive pulled and installed 3 gas tanks this month......so i must ask you.....are you seriously saying pull the tank back out lol......

(sorry for the long story...just kinda funny if you ask me)

 

Well, you could try a larger line from teh pump to th etank, but when you get to the tank bung, you know what is going to happen. If you remove the tank bung, cut off the old return line, drill the bung for a larger (½") tube, TIG in the new section of larger steel tubing, then connect your larger hose, you may solve the problem.

Incidentally, where is your new pump mounted again?

 

I think the regulator is up to the task. I have a Holley 130+gph mechanical pump and it holds steady at 6 psi.

 

nah the AFPR is fine.....mallory uses the sam afpr with their 140 gph pumps....no problem.....i think its good up to like 180 gph...

anyways....i figured that if i ran 3/8 rubber line to the assembly.....it wouldnt help cause it still had to sqeeze into the stock line at the assembly thus making it pointless.....

vader, i was looking at a old assembly i have and thats the exact idea i had when i was looking at in an hour ago....and i said...thats a last resort.

so i hooked the 25 feet of line i bought to the AFPR return and hooked the other end up to the assembly line where it has the stock rubber line in place. just ran it along side the car....i figurted just outta spite, that if i ran the line all nice and neat....the first time...it just wouldnt work.

so after i do this test....my AFPR worked. so i neatly and nicely routed the lines ((*** i LOVE zip ties))....

i corssed my fingers, hooked the lines up and hit the key....look at the AFPR and..........it worked.

i was assuming that since the length of the line from 25 feet to 8 feet would cause the pressure to rise and it not work. buuuuut....it dropped it from a steady unadjustable 9 psi to a very adjustable 5-12 psi area.

5 psi is as low as the line will allow.

so this is a GOOD SEARCH POST. very informative...with a problem that prolly happened to a few people....and this is a solution.

so what did we learn? you can squeeze 140 GPH into the tank VIA 8 feet of 3/8 line running into the stock existing assembly lines and be able to achieve a minimum of 5 psi (which is a lil less than i want , i want 6-7) so ALL is good..... we hope.

 

since i cant edit my posts since im on probation.... (lol) id just like to add this....im utterly amazed it worked. completly shocked. Dumbfounded.

 

oh yeah. i mounted the fuel pump where the fuel filter goes and mounted the fuel filter right under the tank ....looks really good...i need to take pics of it.....once again ...i love zip ties.