Hi Guys I Have A 66 Chevy 2 With A 6.0l And I Am Having A Problem With Either The Fuel System Or Electrial And I Could Use Some Help. The Fuel System Consists Of A Stock Style Tank With A Sump Then Feeds Into A Summit Brand 6" Stainless Element Filter Then Into A Walbro 255 Inline Pump Then To The Intake, The Intake Is A Carbed Style Intake With Edelbrock Rails. The Regulator Sits Between The Back Of The Rails And The Returns Back To The Filler Neck On The Tank. The Feed Line Is -8 Pushlock And The Return Is -6 Pushlock. The Only Thing I Have Different On This Setup Than Most Peole Run Is Where I Supplied Fuel To The Rails. Instead Of Running 2 Lines Under The Intake And Splitting Them At The Front Of The Rails, I Ran Them To The Middle Of The Rails And Welded -8 Fittings To The Bottem Side Of The Rails. This Was Not To Help With Performance But To Hide The Lines So You Couldnt See Them. My Harness Is A Painless Harness With A 98 Pcm And The Car Uses The Stock Body Harness. The Problem Im Having Is When I Drive The Car For Thirty Miles Or So It Will Die, And When It Dies It Sounds Like It Just Looses Fuel Pressure Starts Sputtering The Dies. Once Its Dead On The Side Of The Road You Have To Wait About 15-20 Minutes Then It Will Fire Back Up And Go For A Few More Miles And And Then Will Do The Same Thing Over And Over Until It Just Wont Go Any More. 90% Of The Time When You Crank It When Its Dead It Has Zero Fuel Pressuse But Every Once In A While The Pressure Will Spike And It Will Try To Start But Just Dies. Also The Pump Makes Crazy Noises Like It Has No Fuel In It. This Is About All I Can Think Of Right Now But If Anybody Needs Any More Info Please Let Me Know And Thanks For The Help.
Cody Bray

 

How are the fuel pumps wired? They need to be trigered by the PCM so they will run the 2-3sex test when the key is on. Then When they see a crack signal they will fire up again. So you should be able to cycle the key and build fuel pressure, is there a check ball in the system? also is the car having any other trouble with over heating or anything like that this also sounds like it is going into limp mode or something is wrong with the tune.

 

The Pump Is Wired To A Relay That Is Signaled By The Pcm And Yes The Pump Runs For About That Long When You Turn The Key On. Also The Car Runs At About 180 Degrees All The Time And The Only Thing That Effects The Car Shutting Off Is Outside Temp. When Its 60ish It Runs Fine But When Its 80ish It Dies.

 

Obviously you have a vapor lock problem. Is it carbed or fuelie and what is the fuel pressure? The gasoline is boiling in the line and system is getting vapor instead of liquid. If it's carbed it needs a return line near the engine to keep the fuel cool. You might insulate the fuel lines.

 

i say its time for a front drive cover and a carb and distributor.....

 

with EFI @ 40-60psi FP.
What type of tank vent do you have?
Insufficient/no tank vent will eventually cause a vacuum to be pulled on the tank. This will result in the fuel being at/over boiling point at the pump inlet. [Gas boils at about 135*F, and alot lower in a vacuum.]
The pump noise is the air bubbles in the fuel imploding in the pump inlet. Pump won't last long that way.
The return blowing fuel down the inlet neck will areate it, and it could be too, that the pump is just getting foamy fuel.
I'd suggest that the return should be:
1. As far from the inlet as possible.
2. Directed so it will be below the fuel surface. [Helps to minimize bubbles]

Try the driving w/ the cap off the filler, and see what happens.
The filter is not one designed for a carb application is it? Being it's the primary, it should be 40-100 microns. A final filter of 10 micron size should be after the pump.

 

Echo what Old Geezer said.

Another possiblity is crap in the tank. A buddy had a problem like this that he fought for a year. Replaced the regulator, filters, constantly getting stranded. One day he cut the filter apart and found chunks of the Eastwood tank liner that he tried to seal the tank with. Replaced the tank, flushed the system and was good to go.

If it is nothing thermal (vapor lock), try pulling the pump and filter, back flushing them and see what is in there.

 

Its a brand new tank, has been drained to check for containments, has had 3 different fuel pumps on it, checked the fuel filter many times, changed pump location, added a relay to get away from the wire from the ecm. Bump for making it to power tour,

 

What is the voltage at the pump? I dont like walbro pumps I had one take a crap on me almost out of the box.