DelSolMarine

This is a fully built GSR Turbo setup with 6265 running E85 in a Del Sol. The fuel setup consists of:
Dual Aero 340s in a full blow hanger
8 AN Feed from the hanger to a fuel lab 6 micron fuel filter to a 8an fuel rail
ID2000 injectors
From the end of the rail there is a 6AN line running to a Fuel Lab 535/545 Series Mini Fuel Pressure Regulator with a 6AN return line to the full blown hanger

The issue occurs at any boost level even on 6psi where the car was running at its base pressure of 45 psi and then the car would hit over 50psi fuel pressure and then instantly plummet before 45psi fuel pressure

We checked the entire fuel system to include:
Fuel pump pickups are submerged and not clogged
They are properly wired through a relay directly to the battery and received 13.08 volts through the entire dyno pulls
Blew air through all the lines
checked the fuel filter
disassembled the regulator for inspection

Tuning was done by Matt Shue and several people were there trying to help figure out why the car was dropping fuel pressure. This dyno session started at 4PM and we called it quits at 3AM. If anyone has seen something like this happen before please give some feedback. I will provide links to the other folks that were there so they can provide insight.

mar778c

iTrader: (1)

The regulator is most likely the problem. My friend had the type of same problem. We switched his regulator with mine on the dyno and the problem was solved. I believe he was running on a 60 base psi and it went to 85 psi at full boost. Contact d-rob at IMW as he was the tuner. Also, I think he is now running a Aeromotive regulator.

Ej1ownzu

Blow air thru the fpr reference port and listen for leaks. You can use regulated compressed air at about 20-25 psi or blow thru it with your mouth.

crvtectim

I thought base and overall fuel pressure needed to be a good bit higher to run E85?

sanman000719

if you read again you will see the words ID2000 this means he doesnt need high base

sanman000719

34.5 base here and made 757whp on my id2000's

DelSolMarine

I am thinking that it might be this fuel pressure regulator. Apparently I guess these mini regulators are more for natural aspirated setups and not boost.

Anyone have any replacement recommendations so I can use the 6an lines in and out

92redhatch

I had a similar issue and it was the wiring on the dual walbro setup. I ran bigger wire and it solved my problem

DelSolMarine

I have 10 gauge straight to the battery with a relay... that should be sufficient. and both pumps have there own fuse... each pump reads over 13 volts all the way to redline...

DelSolMarine

should these pumps have a 1 way check valve?

Bugermass

The pumps have check valves built in.. Most likely its your regulator or vac source feeding the regulator.. One test you can do, it do a pull and have somone clamp the return line, if your still loosing pressure with the return line clamped its not the REG and you have a flow issues elsewhere.. If you don't loose pressure then you have a bad reg or bad vac src feeding it.. I have seen 2 of these regs die in the last month on 2 different cars, but do the test first before throwing parts at it.

artie89

iTrader: (4)

with the full blow hanger setup check the hoses that go to the fuel pumps if one of them have a hole you would lose fuel pressure

SOHC_MShue

Yes I believe the regulator is our issue. We went over the entire fuel system and found no other apparent issues. No leaks at the pump outlets, no restrictions in flow, constant 13volts to both pumps, etc.

DelSolMarine

This guy kind of makes a good point. Maybe 13 volts is not enough for these pumps. I really dont know. Below is our email conversation:


ME_______________

Good Morning,

I was on the dyno this past Friday and had some fuel pressure issues.
Everything on the car checked out good from the pumps up to the regulator.
I am using your fuel lab mini regulator with a 6an feed and 6an return out
of it with the 25-90 psi spring. I sent the spring to 45 base pressure and
on 6 psi boost the fuel gauge was reading an increase up to 51 psi and then
at about 6000 rpms the gauge would drop to 30psi on the fuel gauge. I have
heard that several people have had issues with these regulators. Could I
send this regulator in for inspection or get a replacement? Preferably the
larger regulator? I am also running the fuel lab 6 micron e85 compatible
fuel filter that looks good.

FUEL LAB__________

Keith,
What would make you think your problem has anything to do with the
regulator? We have sold thousands of these regulators and I have not had a
single return due to product defect since their release a few years back.
Don't always believe what you read on the idiot boards.

What type of fuel pump are you using?

Thanks,

Brian

ME______________

They are aero340 intank pumps with a full blown hanger.

FUEL LAB________________

The regulator is nothing more than a relief valve. If the pressure drops
under boost, it is because the fuel pump is not able to flow enough to
maintain line pressure due to engine demand.

ME_____________

So even though those pumps are brand new... do you think they are possibly
damaged? I will contact aeromotive

FUEL LAB___________________

No idea. They can troubleshoot any issue with their product.

Muckman

iTrader: (2)

Sold thousands and not a single issue? 100% perfect QA? Please.

Youre not outflowing ANY fuel pump at 6psi. Besides you have two badass fuel pumps. One could be dead and it would still have enough fuel.
At this point I would swap regulators and retest.

kbouchard1092

Yea i dont think any product can be 100% perfect. There is always rare cases. However what he is saying holds true that is is just a relief valve. Seemed pretty cocky and rude to be speaking to a customer.

Swap it out to rule the Regulator at fault. Like muckman said you have two big fuel pumps, there is no way fuel demands of the motor at 6psi is even coming close to max one pump out. Why do you only have 13volts, usually you would have more then that at idle. Even at 13 volts it still shouldnt have issues youre describing at that psi.

Did you monitor voltage at the pumps during the whole tune to see if you had voltage drop when the issue occured?

SOHC_MShue

Exactly. Even if one pump was dead and the other pump was a small walbro 255 it would not have any issue keeping up with that power level. Now for both pumps to be bad then that would be another story, but not likely.

13volts is plenty to keep from dropping pressure at these lower power levels. Definitly not the problem here.

kbouchard1092

I agree 13 volts is plenty. I was more wondering if you show 13volts when the problem is occuring. i do have 14.2 volts at idle, thats the only reason i mentioned it.

I hope its the regulator so you can show him out of 1000 reg there is one that failed.

DelSolMarine

So Ramey built is going to swap a known good regulator on my car tomorrow to rule out if the regulator is bad. A customer approved them to use the regulator off of their car which is really great!

I also question why I am only getting 13.08 volts through the entire pull on the dyno so I am going to wire each pump to its own relay instead of wiring together to the same relay how they are. Maybe that will bump up the voltage a bit. However I do not see that as the problem especially at only 6psi!

I would love to email him back that the fuel regulator was the issue after his cocky and rude comments. Atleast the wording sounds rude but I dont really care I just want my problem fixed.

DelSolMarine

so the regulator is good

pumps are bad and the relay is bad

looks like I am a victim of the aeromotive pump wiring issues in the past. aeromotive apparantly has fixed the wiring of there pumps and I wired the pumps the old way.

putting new pumps in and going back to the dyno!

Muckman

iTrader: (2)

Are you sure the pumps are bad too? How did you come to this conclusion?

darkhorizon

dual stealths would never keep up with 2000s at full bore... But they should work fine up to 50% duty cycle at least.

DelSolMarine

The car is at Ramey Built in Virginia Beach