Help - Fuel Starvation - EFI Setup

[454muscle]

Situation:
Using stock 84 GP gas tank and sending unit -> to electric fuel pump (50 psi) mounted lower than the gas tank -> to fuel pressure sending unit at the fuel rails -> to 60 lb. fuel injectors -> to Elelbrock Proflow EFI system -> to 555 BBC crate motor.

Problem:
Fuel starvation at WOT, and fuel starvation for no apparent reason, uphill/downhill/straight/etc... Fuel pressure just DROPS to 20psi and stays there, for NO reason. The car will idle at that fuel pressure, but will not move (will stall out). While driving, I've had to stop at the side of the road and wait. Took an hour long wait sometimes for it to come back to 50psi, other times, it only took 5 minutes.

I think since the fuel has to go UP through the sending unit -- this is what's causing fuel starvation. But even with a FULL gas tank? WTF?

I don't have a lot of money left and it's currently sitting in the storage unit. I don't want to waste any more time/money if I don't have to. It's a new tank, and my SECOND new fuel pump ($500) since my car was sabotaged with bleach and ****ed those systems up).

What is the "correct" solution for me?

• sump the tank?
• baffle the tank?
• Edelbrock said to mount the fuel pump inside the tank... but how the hell do I do this?
• scrap my tank and pump for a 85 Montecarlo TBI fuel tank, sending unit, & in-tank fuel pump? Does the Monte in-tank fuel pump support 50psi of fuel pressure?

Has anyone converted their setup to fuel injection, successfully? If so any ideas are appreciated!

 

[olds307 and 403]

How does the sock on the pick up look? The TBI pump only puts out 15 psi but a high pressure/volume pump should fit in it's place. What pump are you using?

 

[tc1959]

How does the sock on the pick up look? The TBI pump only puts out 15 psi but a high pressure/volume pump should fit in it's place. What pump are you using?

We have used f-body high volume high pressure pumps on tbi senders for LT1 upgrades. using the stock tank also use the stock f-body sock on the pump.. the pick up on your sender might be too small for the rail pump to suck the amount of fuel you need for wide open throttle demand. Just mt 2 cent's hope you get her figured it out.
Most Gm Port fuel systems run over 60 PSI
even just a few pounds less and the wont run or start. I have seen that on a ton of late model GM trucks. They hate low fuel pressure.

 

[454muscle]

How does the sock on the pick up look? The TBI pump only puts out 15 psi but a high pressure/volume pump should fit in it's place. What pump are you using?

Here's what the sending unit on my gas tank looks like:

With my setup I'm using the Edelbrock 1790 electric fuel pump:

This one ^^ is meant for external mounting, however, can also be mounted inside the tank, but Edelbrock tech. didn't tell me how to do it.

This one would be more suited for an in-tank mounting what will work with my ProFlow setup:

See bottom of this page:
http://www.edelbrock.com/automotive_new ... main.shtml

I'm just at a loss what route to take, what should I do?

 

[454muscle]

We have used f-body high volume high pressure pumps on tbi senders for LT1 upgrades. using the stock tank also use the stock f-body sock on the pump.. the pick up on your sender might be too small for the rail pump to suck the amount of fuel you need for wide open throttle demand. Just mt 2 cent's hope you get her figured it out.
Most Gm Port fuel systems run over 60 PSI
even just a few pounds less and the wont run or start. I have seen that on a ton of late model GM trucks. They hate low fuel pressure.

So can I keep my stock tank and sender? Or do I have to modify them?

 

[tc1959]

I think your idea about the Monti Carlo TBI fuel sender would work,the pump mounts to the sender and picks up fuel through the sock at the bottom of the tank.
This pic is a Camaro TPI sender but they are basicly all about the same.

 

[454muscle]

Ok so gbodyparts.com has this After Market Fuel Sending Unit Hanger Assembly:

If I get that, what fuel pump will work with it? will my current one work?

 

[FE3X CLONE]

It's more than likely meant to be used with a Walbro style pump. A Walbro 340 pump should be enough to feed your engine I would think. How much power are you making?

I know guys running them on 640HP engines with 3/8" feed and return lines no problem.

When does the fuel starvation happen? Would it be by chance after a long drive?

 

[tc1959]

Ok so gbodyparts.com has this After Market Fuel Sending Unit Hanger Assembly:

If I get that, what fuel pump will work with it? will my current one work?

You could probably cobble something together , but it would be a nightmare, I would go and see if you could get a stock GM style High pressure pump, that has equal volume and pressure ratings to match your Injector MFG recommendations.
I have also had good luck with airtex pumps, Them and Carter, Bosch,and Walbro make all the Delco pumps anyway. A stock style pump would be alot easier to fit to that sender.
I forgot to ask if your running a return line to the tank, and a fuel pressure regulator