1998 4630 Fuel Starving

[Chuck87charger]

I have a 1998 NH 4630. It has a single short fuel filter/water separator. Sadly the I&T Shop Manual I purchased only shows the two filter set up, from I assume older models. Sadly my fuel gauge is not working and I ran it out of fuel yesterday. After refueling I made sure I was getting fuel to the filter, but unscrewing the bottom filter drain and to flush any water that may be in it. Once I was getting good fuel, I closed the bottom drain, then opened the top large diameter threaded cover. Once fuel was coming out the top, I tightened the top. The tractor started and I cracked the fuel line at each injector to make sure I bled any air out. After all of this the tractor ran fine for a few minutes, then cut out completely. Almost as if it drained the fuel from the filter than starved again. If I let it sit for a few minutes it started and ran fine for a few minutes. This repeated a few times and I was able to get it back to the house.

Should I blow some compressed air back through the line from the tank? I am going into town to get a new fuel filter, but I only have about 30 hrs on the current unit.

Any guidance on the proper fuel system bleeding procedure and any ideas on my problem would be appreciated.

Thanks,

Chuck

 

[Chuck87charger]

Update. I installed a new fuel filter and blew some compressed air back into the tank. I ran the tractor for about 30-40 minutes this morning on the brush hog without any concerns. I hope we are in the clear.

Wondering if anyone has information on the proper fuel filter replacement procedure on this type of set up since it does not match my operators manual.



Thanks, Chuck

 

[Jerry/MT]

Update. I installed a new fuel filter and blew some compressed air back into the tank. I ran the tractor for about 30-40 minutes this morning on the brush hog without any concerns. I hope we are in the clear.

Wondering if anyone has information on the proper fuel filter replacement procedure on this type of set up since it does not match my operators manual.

View attachment 515901

Thanks, Chuck

If you blew air back into the tank your problem you most likely had a clogged tank outlet strainer. Whatever you blew back is waiting to come back and clog the outlet up again. Might want to consider cleaning out the tank.

Below is a general procedure for bleeding a diesel fuel system. if you have dual filters bleed them one at a time starting with the one closest to the tank.


Bleeding a Diesel Fuel System


Start at the fuel outlet of the tank (inlet to the filter). Shut the tank valve, remove the line at the filter inlet and holding a suitable container to catch the diesel fuel, open the valve. You should have a CONTINUOUS rush/flow of fuel out of the line. If it dribbles or is intermittent, check the fuel cap for a blockage of the fuel vent or the strainer upstream of the valve for clogging. The strainer/screen is attached to the shut-off valve, and is positioned up inside the tank. You will have to drain the tank and pull the valve to clean the screen.
If you have good fuel flow at that point, reconnect the line and open the bleeder screw at the top of the filter. Turn on the tank valve and wait till you have a steady flow of fuel with no bubbles at the top of the filter, then close the bleeder screw.
Your pump may have a bleeder screw. If so, open that until fuel streams out with no bubbles, then close it. If you cannot identify the bleeder screw, loosen the inlet connection at the pump and purge air at that point.
Go back and make sure ALL the fittings in the fuel delivery system are tight so they cannot suck air.
Make sure the battery is fully charged. Loosen the fuel fittings at the injectors, either one at a time or all at once. Crank the engine till you see all fuel at the injector fittings and then tighten the fittings. If you do indvidual fittings, the engine will usually start before you get to the last fitting.
Alternatively, you can "tow-start" it to save wear and tear on your starter. Leave the injector lines cracked open at the injectors at first to purge the lines. Then tighten them up and she should start.
Your injection pump puts out a very small amount of fuel (high pressure/low volume). BE PATIENT. If the lines are totally empty, it takes a lot of cranking to fill them up.
sixbales & Jerry/MT

 

[joecdeere]

there is a strainer mounted into the to of the valve(cut off) that screws into the bottom of the tank, trash most likely stopped it up, when you blew air backwards into the tank, it's very likely that you blew the strainer out of the valve. I would drain the tank if it were mine to be sure all trash is gone and then you can look down into the tank with a light and see if the strainer is missing.

 

[Chuck87charger]

Thank you Jerry. I do not think my set up has a bleed screw at the top of the filter, but if i loosed that cover by hand it appears to have a float in it and I made sure that is getting good fuel. I will consider dropping the whole tank outlet valve and strainer assembly next time I am lower on fuel to clean it all out and make sure the screen is in good condition.

 

[Chuck87charger]

there is a strainer mounted into the to of the valve(cut off) that screws into the bottom of the tank, trash most likely stopped it up, when you blew air backwards into the tank, it's very likely that you blew the strainer out of the valve. I would drain the tank if it were mine to be sure all trash is gone and then you can look down into the tank with a light and see if the strainer is missing.

Thanks, Joecdeere. I did not consider a little air could blow the strainer out of the valve. I will consider dropping the whole tank outlet valve and strainer assembly next time I am lower on fuel to clean it all out and make sure the screen is in good condition.