idles fine dies going down the road

[Dieseltrav]

hey yall first post here, ive got a 94 250 7.3 idi turbo with 220 on the clock, truck used to run fine just occasionally would give me trouble starting, i chased down 2 fuel leaks and got them stopped, seemed to help at first but then it got worse. truck eventually shut off going down the road then started running dead trying to prime, and finally even with cables for 2 hours wouldnt start back up. i converted to an electric pump this weekend but i still stall out going down the road mostly uphill it seems. is it possible the injection pump is failing? fuel filter is rather new, but hardly have any fuel come out of the shrader valve sometimes, other times i have a good bit.

 

[Thewespaul]

Sounds like you have a fuel blockage issue if you barely have fuel coming out of the bleeder valve. You could try a new fuel filter for good measure but you probably have some crud in the fuel tank selector valve that is limiting your flow. What electric fuel pump did you use?

 

[Agnem]

Fuel output from your shrader should be good all the time. Sounds like you need a fuel pressure gauge near the pump inlet to monitor your fuel flow. You may have an issue with air intrusion at the fuel pickup, or something else going on that is pinching off the flow.

 

[Dieseltrav]

Sounds like you have a fuel blockage issue if you barely have fuel coming out of the bleeder valve. You could try a new fuel filter for good measure but you probably have some crud in the fuel tank selector valve that is limiting your flow. What electric pump?

I went with a Holly pump off the shelf mounted in the engine bay, is the selector valve service able or just something to replace? I am currently only running the front tank.

 

[Thewespaul]

The Holley pumps are pusher pumps, so they need to be mounted as low as possible to perform right. Does your rear tank not work when you select it? If so that does also point to a blockage in the selector valve. They are riveted together so they can be taken apart and cleaned but not as simply as most industrial valves. Most people just eliminate the valve and go to a single rear 38 gallon bronco tank.

 

[Dieseltrav]

The Holley pumps are pusher pumps, so they need to be mounted as low as possible to perform right. Does your rear tank not work when you select it? If so that does also point to a blockage in the selector valve. They are riveted together so they can be taken apart and cleaned but not as simply as most industrial valves. Most people just eliminate the valve and go to a single rear 38 gallon bronco tank.

Maybe I will just try and bypass the valve for temporary and see if I can clean it. I didn't think of blockage but that's a very strong possibility. I bought the truck and it had been sitting for several years and I ran it low on fuel 2 or 3 times because the gauge is wrong, blockage is very likely

 

[Thewespaul]

I wrench on nothing but these IDIs and blockages from the pickups falling apart, rust and algae from these things sitting for long periods of time causes lots of similar issues to what you’re experiencing. Keep us posted, hopefully the bypass fixes your problem.

 

[Dieseltrav]

I wrench on nothing but these IDIs and blockages from the pickups falling apart, rust and algae from these things sitting for long periods of time causes lots of similar issues to what you’re experiencing. Keep us posted, hopefully the bypass fixes your problem.

Any tips/tricks for bypass? Haven't looked at it, sounds simple, just wondering what some of y'all have run into

 

[Slicknik]

@Dieseltrav not to contradict anything that has been said , but if your truck runs fine at idle but you have issue driving down the road and up hills wouldn’t your culprit be the pick up tube in the tank? Or your tank selector is bad and is semi-clogged ?,

Assuming your gas gauge works are your problems happening under or around 1/4 tank? I would replace the pick-up tube and bleed the system again using the Schroeder valve.

This of course is assuming your electric fuel pump is working correctly and is after the tank selector before the fuel filter. May have to clean the tank and clear fuel lines with high pressure air

 

[Dieseltrav]

Is my filter going to be more prone to clogging due to the bypass? I

@Dieseltrav not to contradict anything that has been said , but if your truck runs fine at idle but you have issue driving down the road and up hills wouldn’t your culprit be the pick up tube in the tank? Or your tank selector is bad and is semi-clogged ?,

Assuming your gas gauge works are your problems happening under or around 1/4 tank? I would replace the pick-up tube and bleed the system again using the Schroeder valve.

This of course is assuming your electric fuel pump is working correctly and is after the tank selector before the fuel filter. May have to clean the tank and clear fuel lines with high pressure air

At 1/4 tank my truck will shut off out of fuel, originally I only had problems when I first ran it low on fuel. Now it's full tnk and still having problems.

 

[Dieseltrav]

Attempted to do the bypass last night, I got halfway done but need more fuel line to finish... Will finish tonight, it's quite a b*tch where the selector is mounted

 

[Thewespaul]

It sure is. I just slide 3/8 fuel hose works well over the nylon line, it’s especially not fun on the cab and chassis trucks

 

[Dieseltrav]

the bypass has failed but im not sure if i have the pump connected to the pickup or return in the tank. going to switch lines later and see if that changes anything. also working on removing the tank for it to be cleaned and to check the pickup in the tank

 

[chillman88]

the bypass has failed but im not sure if i have the pump connected to the pickup or return in the tank. going to switch lines later and see if that changes anything. also working on removing the tank for it to be cleaned and to check the pickup in the tank

Feed is 3/8" return is 5/16".

 

[Dieseltrav]

fuel tank is out! going to clean it tomorrow. was hoping for insight on reinstalling the factory strainer vs putting fuel line down to the bottom of the tank? the old strainer is in pieces in the tank and i would like to avoid that from happening again, also i would like to have full range of my fuel gauge vs running out at 1/4 tank. (still having 7 gallons unused at the bottom) any help or comments would be great!