Free pat on the back for whoever solves my fuel starvation issue!!!!

[challngd73]

Ok, this is driving me nuts and I'm at my wits end here..  73 440. F.a.s.t. Ez efi system, electrical in line fuel pump.  The system is supposed to go up to 60psi at the fuel pressure regulator, however, 43 psi is what it is supposed to be set at unless your horsepower is around 550.  I could only get around 40 psi.  Car still ran fine at 40.  However I had to limp it home the other day, and once at home, you could here the fuel pump whining badly, and the fuel pressure was bouncing between 15psi and 30psi.  Gas tank wad full so that is not the reason for starvation.  Figured the fuel pump may be a goner so f.a.s.t. Sent me a new one.  Installed it and after it warmed up, same issue and fuel pump was again whining.  Next I figured it could be a bad fuel sender with a clogged sock.  I replaced the fuel sending unit today and after doing so adjusted the fuel pressure to the 43 psi it is supposed to be at with no problem...good sign..and drove it.  Drove fine at part throttle, but as soon as you step on it, it cuts out like it's starving.  The car ran fine until a few days ago, then this issue sprung up.  The last hope I have is this....
  The guy who installed the f.a.s.t. Kit used my factory 5/16 metal fuel line from the gas tank to the fuel pump, which is mounted on the passenger side frame rail.  I am wondering if maybe it has sprung a pinhole leak in that original metal line that is sucking air, and dropping my fuel pressure and over heating the pump.  I bought a 3/8 metal line that I am going to run from the tank to the fuel pump...if that doesn't work....I'm out of ideas.
Does this sound like a likely fix, or does any one else have another  possible cause?  Pleease?  Anyone..

[acudanut]

43 PSI would be nuts., fuel going into a carb should not be more than 7-12 psi on a carb. However, I realize you have a EFI....Why ?? Go to a Carb and be done with the issues.

[challngd73]

43 PSI is nuts...Your fuel going into the carb should not be more than 7-12 psi.

  My 440 is fuel injected..no carb

[acudanut]

43 PSI would be nuts., fuel going into a carb should not be more than 7-12 psi on a carb. However, I realize you have a EFI....Why ?? Go to a Carb and be done with the issues.

Read the entire post...WHY EFI ?

[challngd73]

Read the entire post...WHY EFI ?

I'm just looking for some troubleshooting ideas on what could cause the fuel starvation, not debate the benefits or downfalls of each system.  I had the carb, and had plenty of issues with that.  Car ran better with the fuel injection than it ever did on a carb until this issue arose.  So, going to a carb is not my answer here, any thoughts people?

[Cooter]

Well, First off, F.I. units require high pressure as well as high volume when dealing with high HP engines. 5/16" fuel line would be my first place to start.
Once upgraded, I'd try it and see if it did in fact stop the problem. However, if not, I'd then look into a High Volume fuel pump as well. FAST should have sold you the correct volume pump to begin with, but again, mistakes happen.

How do you know it's a fuel starve issue? Many things dealing with fuel injection can cause the same symptoms you describe....A simple way to tell if it's a fuel problem is to run a vacuum line from intake all the way into the car and have a buddy with some carb cleaner "Spray" it when it begins to "Starve"..If engine picks up, you know for sure it's fuel related.

Some of the things I've seen cause a "fuel starve" like symptom is A bad TPS 5 volt ref. Signal, Bad ECU/PCM, Bad Mass AIR flow Sensor, etc. Course, this was dealing with Stock F.I. but basically the same.

[73Chally]

Does this only start happening after everything has warmed up, or right from the moment you turn the key?  Are there any rubber lines that might have a small pinhole or tear that could get worse as the tube gets hot?

[Cooter]

BTW: Is this FAST system Programmable? Meaning, you hve to set the fuel curves and maps? Is It Port Fuel injection or T-Body?

[72cudamaan]

Switching to a 3/8 line may help, but I'm a little more concerned that you were only able to get 40-43 psi at the regulator
when the pump is rated for 60. Even a pinhole leak behind the pump wouldn't be enough of a problem
to lose pressure. Is your regulator on the pressure side of the system or on the return side? Most if not
all oem set-ups are on the return side aka after the injector. Just some thoughts

[GoodysGotaCuda]

Gas cap vented? 

Sometimes it's the dumbest things

[Chryco Psycho]

is there a filter between the tank & pump ??  Is the in tank filter blocked ?
I have seen it before where the pump whines because the filter is blocked & starving the pump .

[challngd73]

is there a filter between the tank & pump ??  Is the in tank filter blocked ?
I have seen it before where the pump whines because the filter is blocked & starving the pump .

Filter is clear..

[challngd73]

Switching to a 3/8 line may help, but I'm a little more concerned that you were only able to get 40-43 psi at the regulator
when the pump is rated for 60. Even a pinhole leak behind the pump wouldn't be enough of a problem
to lose pressure. Is your regulator on the pressure side of the system or on the return side? Most if not
all oem set-ups are on the return side aka after the injector. Just some thoughts

After replacing the pump and fuel sending unit, it has no problem getting 60 psi...  Until the whining occurs.

[Strawdawg]

sounds like the pump is getting hot....does the fuel pressure drop at this time?    Being that it happens in normal driving as well, it is not a fuel line problem per se, but, I am surprised he did not use 3/8".

Is the return line working or is this a single line system?  Not a Walbro pump, is it?

[Chryco Psycho]

the other possibility could be the regulator ,but I doubt it , if the pump is quiet & holding 60 psi & when it starts to whine the pressure drops off it has to be a pump or suction side problem