EFI Fuel Problem

[Roadtoad]

Here is the situation. I have a 74 Bronco with a 90 Mustang HO that was installed about 4 years ago. I have a 24 gal standard tank from BC with a stock side tank. I have high pressure external pumps on each tank before a switch valve to select which pump and tank are selected. These are both external pumps.

The problem that I am having is that the vehicle will run for sometimes up to 2-3 hours without missing a beat. All at once it will start sputtering and die. Sometimes I will switch tanks and it will fire up again and run right away. I will run on that tank for maybe 15-20 minutes, switch it back andrun for another couple of hours. Sometimes, I have waited about 5 minutes without switching tanks and it will run again for a long time.

Both of the external pumps are located close to the tanks with truck type filters between the pumps and tanks. I have changed the filters often without any improvement.

Any and all help would be appreciated

[blwngsket]

Is there any problem with the tanks venting? I had a motorcycle that would run fine from Sac to Vallejo and then start cutting out and die. after a couple minutes it would start and do it all over again, usually after pulling off the gas cap to check if I was out of gas. Started to leave the cap loose and the problem stopped. Turns out the one way check valve on the vent line was bad. Removed the valve and problem gone.
Just an uneducated guess. I have an 89 5.0 in mine that I know nothing about.
Good luck.

[Cheesenip73]

How about some more help for my dad guys. I don't have EFI, I'm at a loss. Chime in.

[NorcalKD]

Did you hook everything up like how it shows on www.fordfuelinjection.com? That would be my first course of research. I have never had this issue before, since I eliminated the stock tanks and went with the rear 24gal tank w/ intank pump.

[crawlin68]

I would check to make sure that the tank(s) is well vented. Sounds like your tank might be pressurizing and the pump can suck any gas out of the tank, starving the engine. Have you tried removing your gas cap right after the engine sputters and dies? And then see if the it will restart?

[highlander]

I was having similar issues when I had dual tanks and it ended up being a bad Pollack tank selector valve.
Does it only happen when pulling off one of the tanks, if so it could be a fuel pump working intermittently.

[Cheesenip73]

RoadToad, you gettin this? Great starting points.

[Roadtoad]

Thank you very much to those that are trying to help an old Bronco guy out.
I am checking on all of these things and hope to report back about the findings.

[crawlin68]

Thank you very much to those that are trying to help an old Bronco guy out.
I am checking on all of these things and hope to report back about the findings.

Doesn't it have to be drivable in order to check these things? (he he)

[welndmn]

Check the Black and White/Gray plugs behind the intake as well.
Then pins get loose on those.
Give them a good shaking when it running and see if it stalls.