1993 7.3 fuel runout

[Crazy Chris]

Hey guys I'm new here and recently purchased a 1993 7.3idi manual truck that has a 1994 factory idi turbo motor installed. Ran great when I first bought it but now I'm having issues. Truck has a new tank selector valve and lift pump. Injectors lines have been rebuilt. Now the issue I'm having is driving down the road it acts like it runs out of fuel, sometimes it will pick back up and drive normal but the other day it didn't and stalled out. Pulled fuel filter off it was about 3/4 full topped it off with diesel kleen and spun the motor a while with 1/4 throttle till it started back up. Only time it is hard to start is when it has the "starving fuel" issue. Any ideas? Do I have a injector pump on the way out? I have looked for leaks everywhere and haven't seen anything. The filter is never dry and always has a good bit of fuel in it when it is acting up.

 

[Thatoneguy]

Sounds like injector pump. No bueno.

Sent from my VS980 4G using Tapatalk

 

[sjwelds]

Could easily be air intrusion.

Edit: what is the fuel tank level when it acts up?

 

[Macrobb]

Pulled fuel filter off it was about 3/4 full topped it off with diesel kleen and spun the motor a while with 1/4 throttle till it started back up.

You have air getting in. Look from the lift pump* backwards towards the tank. IP can't cause this.

(after the lift pump is under pressure, so it would leak fuel out, not air in as long as the engine is running).

 

[icanfixall]

Welcome to the forum. Please tell us what level the fuel tanks are at when this happens. Your sucking in air to the fuel system somewhere and it sounds to me like the tank levels are around 1/4 tank. If so then my guess is the fuel tank pickups have broken off and you can't use the last 1/4 tank of fuel. This is a "normal" issue with our trucks. Easy fix is never allow the tank level to reach 1/4 tank.