New member first post.
My 2006 Task master 425A, Y385 motor, stopped running a month or so back. It has only 75 hours on it. Changed the fuel filter and bled the system, but still no go. Fuel gets through the return line back into the tank all right. Pulled the injectors to take them in for a check to see if they are squirting at all. But with them disconnected, and turning over the motor, I don't see any fuel coming out the injection lines. That makes me wonder if the injection pump is bad. Kind of acts like it does if you leave the kill switch pulled out and try to start it. BTW, disconnected the kill switch to see if it wasn't returning to the operating position, no difference.
Anyone know the name/part number of the injection pump?
Thank you all
What exactly were you doing when it quit? Did you run it out of fuel? how exactly did you bleed the system? No fuel from the injector hard lines could be caused by air trapped in the system. There are several steps in a proper system bleed.
1. Get fuel to the filter bowl. Turn on fuel valve, glass bowl should be full of fuel. there is a screen filter on the fitting that goes up into the tank. If it is clogged, there may be fuel in the bowl, but it is incapable of flow just lig\ke if the fuel valve was shut off.
2. Get fuel from bowl to IP lift pump. The IP has two pump functions. One is a lift pump to draw low pressure fuel to the pump and thru the filter, and second is to force it at high pressure to the injectors. Just forward of the throttle lever on the pump is a screw-on cap with spring under it(the stop lever is almost touching it when in the run position. This is the manual lift pump to help move fuel and purge air from the system. You unscrew it and it should pop up on a spring. Pumping it circulates fuel thru the system without cranking the engine. There is also a screen where the fuel line from the tank connects to the IP housing. Same as screen up at the tank, if clogged, you get no flow... Quick check for fuel flow potential is to disconnect the line where it connects to IP, put it in a bucket and open the fuel petcock at the tank to see that you have a good stream of fuel into the bucket. Having flow back into the tank on the return line is a good thing, so you probably have Ok fuel flow thru the screens.
3. Purge air from filter then from IP housing. On top of the filter housing there is a 10MM bolt. loosen it and pump the manual lift pump till fuel comes out, then re-tighten it. on the top of the IP, near where the hard lines are attached are two 10MM bolt heads, one with a ring thru it. Those are bleed screws. loosen them and pump the lift pump till fuel comes out of these locations. If there is air in the top of the IP, you will get no fuel out of the hard lines, as the individual IP plungers, if full of air, cannot develop enough pressure to push it past the little check valves at the bottom of the hard lines... You can have flow back to the tank, and still have air in the top of the IP!
4. Purge air from injector hardlines. Once the air is bled out of the top of the IP housing, set the throttle on a high setting, and crank the engine over with the compression nuts up at the injectors loosened. If you have a compression release lever, use it to save wear on the starter. If all the air is out of the IP, and the previously mentioned screens are capable of allowing fuel to flow, you should fairly quickly have fuel flow up to the injectors. Once you get fuel out of the injector compression nuts, tighten them back down and see if it will fire... Another test, if you have the injectors out, is to reconnect them to the hardline, but pointing into the air instead of the engine, to see if they will pop/spray fuel. Be carefull atomized diesel fuel breathed, or high pressure injected into/under the skin is really bad for you...
If it fires and runs, go back and re-bleed the 10MM bolts on filter and IP to get rid of any small ammounts of air remaining in the system and which will have collected at the high points where bleed screws are located.
If it dosn't run with fuel to the injectors, the injectors spraying into the air is a good test of IP/injector function. If the injectors won't spray, but you are certain ALL the air is out of the IP and hard lines to the injector, you probably have an IP issue If it will spray, but still won't run, you probably have a cylinder compression issue(not enough compression heat to fire).
Good Luck...
