I just installed a new fuel system on my Trans Am. Here is the rundown of what was installed.

Twin Intank Fuel Pumps (Walboro GSS340)
(2) -6 Lines out of the tank to Earls Y-block Exiting to -8 Feed Line
Russell Performance Competition Fuel Filter Part # 650103
http://store.summitracing.com/partde...5&autoview=sku
Aeromotive EFI Fuel Pressure Regulator Part #13114
http://store.summitracing.com/partde...5&autoview=sku
Trickflow LS1 Fuel Rails
http://store.summitracing.com/partde...5&autoview=sku
Return is a -6 coming out of the regulator, attached to the factory feed being used as a return line. (The factory regulator was taken out of the factory sending unit.)
Autometer Ultra Lite Electronic Fuel Pressure Gauge Part #4463

I will also add that I did change over to a plastic 99+ Tank in place of the Steel 98 tank I had due to ease of installation and service. All of the evap stuffwas taken off. I do have the EVAP line running from the intake, using the factory line, back to the tank, connecting in stock location.


Here is my problem:

I primed the car about 15 times and only got about 24 PSI.

I than remember the regulator may need to be adjusted. I came inside and went on Aeromotive's website to make sure on how to adjust the regulator. They did not have my regulator listed but used the closest one as they should all operate on the same principal as far as adjustment goes.
Here is my reference:
http://www.aeromotiveinc.com/pdf/13101.pdf
It says they are shipped with a preset of 43 PSI. I figured that can change so I proceeded to adjust the screw on top of the regulator.
I went all the way in turning clockwise, which was not very much. I than primed the system again.

The Pressure did not change. I than tried screwing the nut the other way until it about came out. Still NO change in pressure.

Now the pressure does hit 23-25 psi and falls right off after the pumps turn off. I cant remember after priming the system how long pressure is supposed to hold

Now I am a little lost.

For a quick rundown since I do not have any pics. The -8 Feed comes in through the driver side fender. The regulator is mounted to the fender with the front of the reg. facing out. The return runs straight down and makes a gradual 90 deg. turn into the factory feed line. The fuel is supplied to the rails off of the regulator with a straight -8 fitting off of the regulator going to a full flow 90 deg. fitting into a -8 Gauge adapter (FPSS is used there) the adapter is than hooked to the rails, so there should be no interference there. The rails are connected in the back using 2 -8 Full Flow 90 deg fittings into each rail and a piece of -8 line between them. That line has a gradual bend as it should with no kinks.

Now my pressure sending unit is mounted at the end of the passenger side rail after a -8 - -6 reducer. (This was installed for my nitrous solenoid to adapt to the 1/8 inlet.) The sending unit is installed before the solenoid. The gauge did work before I started the installation, it was installed on my factory rails. At first I thought this could be why it is reading low, but the fitting is RIGHT at the end of the rail. It should get the same pressure no matter where in the feed side I put it. At least that is what I am assuming. If that is all the pressure I am getting to my fuel solenoid, I am in trouble!

I checked everything for kinks. There are none. I also checked for leaks... none.

To connect the pumps to the sending unit I used high pressure fuel hose and injection clamps, so I do not think that is the issue.

The only things I can think of are either:

A: Bad regulator.... but it is brand new, not sure how likely that is.

B: Fuel filter on backwards. There was no flow direction on the filter when I installed it. I just installed it with the Russel Logo reading left to right, with the left side being the inlet and the right being the outlet. I looked on Russell's website and there is nothing there on it. I also looked at overviews of it on misc websites and it is for an injected car but there is no specification on which way flow should be directed.

C: Bad fuel sending unit for the Autometer gauge.

Here what I plan to do to check everything over.

1. Use a handheld gauge and check pressure at the Y Block at the back of the car using the 1/8 port in the Y Block.

If that checks out ok.

2. Install an adapter between feed line and inlet of pressure regulator and check pressure just before regulator. Still using a hand held gauge.

If thats good

3. Remove FPSS and check pressure on the driver side of the rail, right where the fuel comes in after the regulator.

If thats good

4. Remove sending unit for gauge and check pressure there.





Now I am pretty sure I am taking all of the steps in checking possible. Too late tonight to do anything. Before I get at it tomorrow, I want to ask everyone here if they have ever had this same issue, or might be able to shed some light on my problem. Is there anything else that could be wrong that I did not already check? I have installed about 8 fuel systems like this in the past. This is my first using this regulator and filter. I usually use an Earls filter that HAS the flow direction marked on it. I chose this regulator.. becuase it was black and matched everything else, its specs the same as the other regulators. The only difference is it is approved for marine use.

Sorry for the lengthy post but I wanted to answer any questions I can before they were asked. Thank you for any help you can provide.

 

I forgot to mention both pumps are hooked up to run full time. They both def. on as they are a bit louder than the single Walboro 340 I previously had in the car. These are both brand new pumps. Actually everything is BRAND NEW. Except the FP gauge that as I mentioned before worked on the stock rails.

 

Is your regulator before the rails? Mine comes into one rail, crossover into the other rail, then into the regulator then back the return. If I read the description right yours feeds the regulator then into the rails.

 

2 things come to mind:
1. The comment by 98SS is correct. The regulator should be AFTER the rails are fed, not before.
2. The main pump volume is being returned to tank thru the secondary pump. [Assuming they are not both on at all times.]
A check valve should be used between the 2nd pump, and the "Y" block, to prevent this.

First, I'd straighten out the reg plumbing.

 

The pressure is regulated before the rails. I have done this same setup on 3 other cars before mine and never had this issue. I am waiting for Aeromotive tech to call back.

 

Both pumps are running full time as mentioned in the original post(s).

Again, I have set this up the same way 3 times in the past and the pressure was never an issue.

 

Did you use the same regulator the previous three times? These regulators aren't made to be used as an in/out style regulator like on carbed setups. Usually they're two or three inlets with a return. Maybe your regulator doesn't like being used this way?

I'm trying to looks up the specs on that part# now...

 

No the regulator is not the same. I am beginning to thing that may be the issue. I will know for sure when Aeromotive tech calls back.

According to the link on Summit's site it in an inlet/outlet/return type regulator. So it sounds like the setup should work.

 

I saw that on the Summit link you posted also. Then I found other info to a place that sells them on ebay and it had the same things listed, but in the description it said it had two -10an inlets and one -6an return. Something doesn't add up...

 

lol Ill trust Summit before an Ebay site, but Summit has been wrong before. I just wish Aeromotive tech would call back already so I know if I will be re plumbing my fuel system tonight.

 

I just talked to Aeromotive tech. He told me that the setup I have is fine, but not optimal which I understand, and understood going into this setup. This fuel system is overkill for me anyway, so I do not need peak performance from it.

One stupid *** thing I did NOT due is put a allen wrench to the adjusting stud on the top of the regulator. I was only using finger pressure. I guess this is what I get after 2 straight days of busting *** on the car and not using my damn head.:ba ng:

Hopefully once I turn that adjustment **** in the way I should have everything will be fine.

 

The site shows the system layout, in the order of connection...
The reg is not before the rails..
http://www.aeromotiveinc.com/d_syste...temdisplay=efi

Have fun....

 

Glad it worked out. It's always the simple stuff that gets me too.

I have to say, I've never heard of anyone on this board plumbing a fuel system this way. It should work I think - you're basically making a shorter version of the stock demand type system we already have (stock). The tech was right though, not the best way to do things... I imagine pressure surging could be an issue, as well as priming.

What made you want to do it this way, if you don't mind me asking?

 

There were a few reasons. I have done this on cars that have made 800 RWBoostedHP and it worked out great.

My car on motor is not making near the power on motor to need this fuel system. This is so I can safely spray a 2-300 shot if I want with my wet kit. I had alot of the parts already and it was cheaper than buying a dedicated fuel cell. This also provides a good source of fuel to my nitrous solenoid when I do spray the car with the end of the pass. rail feeding directly into the fuel noid.

In all reality I am probably only going to spray a 150 shot due to the 4L60 in the car and not having the money to put the TH400 that I want in the car. I may have even been safe on only 1 pump, but that is not something I wanted to risk the thousands of $$$ I have in the engine. I figured overkill is better that not enough.

Plus it looks pretty cool.

 

I understand that as I said before. I talked to Aeromotive and they said that my setup will work good for what I am doing. They also said that it is not the absolute best way to setup the regulator, but agreed that what I want it for will work great.