Fuel system purge/priming

[jgeissin]

I have an OLD B9200HST. Over the winter I THINK I had water in the fuel (not sure), so since then I have cleaned the tank and the fuel lines up to the pump. Cleaned an otherwise new fuel filter and replaced several hoses as well as the O rings for the filter fixture.
I have been trying to prime the system, but have had no luck.
I can pressurize the system by taking off the fuel return line on the left upper side of the tank and putting my air compressor nozzle to that, using low pressure. With that, I can make fuel flow up to the valve that is mounted on the injector block (I assume that that is what it is called, all the injector fuel pipes leave this block).
SO, I have fuel flow (pulses) when I turn the engine at that valve (remove the hose and open the valve). When I remove the injector pipes (loosen them at first) to see that there is fuel flowing up to that point, I get nothing. I took the first pipe totally off and I can see fuel pooled there at the fitting, but when I turn the engine (both with and without applying pressure to the fuel tank) I get no motion of that fuel. This is the fitting right on top of the injector block where the pipe to the injector attaches.
Do I have a problem with the injector block?
I have looked closely at the fuel cutoff and the throttle controls, but i have not disassembled any of that yet. Trying to keep the dirt and my inquiring mind OUT of where it should not be!
Looking for direction here!
Thanks!

 

[rentthis]

When you remove the fuel supply line to the filter assembly, do you get good fuel flow? If not, you need to check the tank again for an obstruction at the fuel pickup or an internal problem with the fuel line. If you have to pressurize the tank to get fuel flow, you have an obstruction in the tank or the fuel line. If removed from the filter assembly, the fuel line should free flow.You can also blow air back through the fuel supply line from the engine back into the tank to temporarily dislodge any blockage. Doing that will eliminate or confirm problems with the first part of the fuel system. From there, my advice is to follow your current thoughts and stay out of the injector pump. That's for people like Wolfman.

 

[North Idaho Wolfman]

First thing, put the air hose down, all you will do is damage the complete fuel system.

Start at the fuel filter pull the filter cartridge and turn on the fuel, should get good flow.
Next pull the line that feeds the injection pump, again it should have good flow.
On the top of the injection pump loosen the injector lines, make sure the stop lever/cable is not stuck on, crack engine should have fuel coming out in small pulses, if you do not then you have a linkage, stop lever, solenoid, or injector pump problem.

At that point if it's still not doing anything, I would suggest you get the WSM for the tractor, that will help with removing the injector pump and sending it in for service.

 

[jgeissin]

I get natural gravity flow when I open the fuel filter, those lines were cleaned/replaced.
I can blow fuel up to the valve that is just after the fuel pump (mounted on the injector pump/housing).
When it is all put together except leaving the lines off the injector housing so that I can see if there is flow OUT of the injector, I see nothing (using normal engine cranking).
This engine has never been run without the fuel filter, so junk from the system should not be in the injector pump (in theory).

How high should the 'spurt' be out of this valve from the fuel pump?

 

[rentthis]

From what you describe, it does sound like an injection pump problem. You should get positive pressure when cracking the lines on the top of the pump or when you crack the lines at the injectors.

 

[North Idaho Wolfman]

How high should the 'spurt' be out of this valve from the fuel pump?

Not very high, maybe a 1/4 inch.

If you get stumped, I would suggest Pulling the pump and sending it to be tested, along with the injectors.

 

[jgeissin]

I THINK I'll take the pump off and check the diaphragm. New pump is not as bad as a new injector block! ($40 vs $1000). This tractor is FAR from dead! It may look like it, but it has allot of life left!