AFASTYZFR1

iTrader: (55)

Need some help guys:

Parts being used
Procharged F1-C making around 13psi
80lb injectors
Edelbrock rails
-6 line
Kirban regulator
Dual Aeromotive 340 Stealth pumps
Y-block in tank with all AN fittings

Build thread on car: https://ls1tech.com/forums/forced-in...1-c-build.html


Problem:
Under wide open throttle fuel pressure drops at 5500 rpms to about 40 psi (car is making 783rwhp through a 4l80 when fuel pressure falls)


Troubleshooting:
When it primes on key on is goes to base fuel pressure which is around 55psi and falls to about 40 psi and holds.

When air compressor is hooked to regulator for boost signal, the fuel pressure can rise all the way to 100psi

Does the car really need more pump?

Lonnies Performance

iTrader: (16)

Twin 255 pumps will feed your engine, so I"m not sure why it is dropping with two 340's, other than you have a bad pump or pumps.

blue00ZZleeper

iTrader: (5)

Isn't -6 a little small of a supply line too? Being a 6spd car this makes more to the flywheel then mine and I saw a little bit of pressure drop too. I was running the stock feed line with 2 GS-340's and an Aeromotive regulator. I think the fuel demand might just be a little to high for the line?

whiteboycntdnce

iTrader: (5)

The car originally had twin 255's, but after doing some tests to ensure there are no leaks and that the regulator was functional, it seemed logical that the car was simply out of pump... However, it's still having the same problem... Very doubtful that 2 255's and 2 340's were/are all faulty.

djfury05

iTrader: (30)

I agree. Best bet for the future would be -10 an feed and -8 an return.

MIGHTYMOUSE

iTrader: (59)

need pics of what is in the tank.

also did you happen to add a filter after the pumps?

whiteboycntdnce

iTrader: (5)

Yes there is an in-line filter mounted under the car.

I'll ask Mike if he can take a picture of the bucket setup.

AFASTYZFR1

iTrader: (55)

MIGHTYMOUSE

iTrader: (59)

Ah take out that filter!

tunedup

How'd you connect those steel braided lines to your pumps?
Are those line submersible? Rubber or teflon lined?

AFASTYZFR1

iTrader: (55)

Think you were right David. Tim had this small filter on the car:

http://www.jegs.com/i/JEGS+Performan...15030/10002/-1



There is braided fuel line in the bucket

tunedup

I was wondering how you attached the steel braided line to the pumps since the pumps just have the regular nipple on them like the stock pump?
If you had this same problem with the walbro pumps it sounds like there maybe something else common between the setups that changes after use causing the drop in pressure.

Lonnies Performance

iTrader: (16)

Removing the filter is not an appropriate solution....

Replacing it with one that can meet the flow requirements is the best solution.
I recommend a 10micron to properly protect the injectors.
When in doubt go big on the filter... that filter you linked to belongs on a lawn mower.

whiteboycntdnce

iTrader: (5)

Do you offer anything?

ss1

iTrader: (32)

One of the braided lines coming out of the sending unit looks to have a pretty tight radius and looks like it might be kinked a little. Since you have easy access to removing them you might want to try using a 90 degree fitting on the left (lower) hose and a 45 degree fitting on the right (upper) one. If the system will hold 100psi there shouldn't be a leak anywhere, so it must be a restriction.

MIGHTYMOUSE

iTrader: (59)

told him to remove the filter to see if it is the restriction

duh to installing the right filter after that

Lonnies Performance

iTrader: (16)

Just replying to what you typed, not what you implied or what was discussed other than above. I figured you knew better, but it cannot be assumed for all those reading this post.

Many so called "experts" do not run filters & rely on the socks to protect the injectors.
I wanted to make it perfectly clear that you need a good inline filter in all circumstances.

AFASTYZFR1

iTrader: (55)

Proper fuel filter solved the problem