Diesel guys...

[Steinberg]

Got a 99 International 4900 with the DT466E (Navistar) diesel. It's difficult to start if it hasn't been run in a while. It will sputter just a bit on the first crank and die. Then you gotta crank it for 20-30 seconds before it will start to sputter again and finally fire up. It happened when the weather was warm as well as now. My guess is that the fuel pressure is leaking down slowly... any thoughts or other ideas?

[Rockn4x4]

One of our farm trucks was like that, but I cant remember what was causing it.

[tsmall07]

There is a good chance you have air entering your fuel system. Diesel fuel systems have negative pressure instead of positive, so air will enter the system instead of fuel squirting out. You'll need a new gas cap, schrader valve, air pressure gauge that can read 5psi, and some drill bits/dikes (the tool not the girl). Drill a hole in the gas cap and cut away enough of the top to get the schrader valve through. You'll need enough space to attach an air nozzle also. Seal the schrader valve into the gas cap with some silicone. Put the gas cap on the tank and pump air in until you reach 5psi or so. Creating positive pressure in the tank will push fuel out of whatever hole you have in the system. If the system remains at 5 psi, you know that you don't have a leak. It may not be a visible stream of fuel, but it should weep enough for you to find the leak. You should do this right after the truck is run for a while so that the fuel system is fully pressurized.

[ford150]

it is fuel leak problem... cant find the problem ill take a look at it or you can bring it doves truck service in cburg

[ford150]

.........fuel tanks have vents for pressure

[TerryD]

from what little i know about diesels and what i know about fuel systems, it sounds like the injector pump is losing its prime. I'm unfamiliar with the injection system on this engine, but on a tractor, the first place to look would be the primary (low pressure supply) pump from the tank. sounds like the check in it has died? I know older fords and most industrial engines i've delt with have a small mechanical pump that provides the primary pressure to the injector pump and they use the standard reed valve system. if that pump (if it has one) has a bad seat at the inlet reed then the fuel will flow back to the tank when the engine is off for an extended period of time, high rpm ( ) operation may suffer because of reduced feed from the damaged pump. just my .02 on it. again, not a diesel guy.

[tsmall07]

.........fuel tanks have vents for pressure

They must not all have vents. I know a guy thats done it on a cucv.

[hklvette]

I'm with terry on this one. Check the lift pump (the one in or near the tank) to see if its check-valve isn't dead.

[tsmall07]

http://www.dieselplace.com/forum/showthread.php?t=87582