B7800 fuel shutoff stuck off

[Dronez]

I have a B7800 that won't start. The solenoid clicks and the plunger pulls back when the key is turned on, but the plunger does not engage anything inside at the pump. I took everything loose from the fuel injector pump and it won't come out of the hole?

 

[North Idaho Wolfman]

You need to line up the fuel rack with the slot to get it out.

 

[Dronez]

You need to line up the fuel rack with the slot to get it out.

I have seen several right ups that say that but it appears that a frozen fuel rack may be the problem. If this is true then the pump is locked into the shutoff position and I can't move it to allow the removal of the pump. Not sure what my next step should be?
I have everything disassembled, speed control to access it from the side, shutoff solenoid removed, pump mounts removed but it won't come out of the hole?

 

[North Idaho Wolfman]

Yes if the rack is stuck then it makes it really difficult to remove the injection pump.
Try and gently force the rack in place, there is really no other way to get the pump out.

 

[Dronez]

Well I finally got it out. The fuel rack was frozen in the forward (shutoff) position which meant that it was protruding out from the front part of the pump. That rack sticking out far enough to prevent the pump from coming out of the hole. After I managed to force it out I took off the little cover plate on the side exposing the rack. Three of the four plungers were rusted in place. I took the pump to an overhaul place today to see if it can be salvaged. Thanks for your expert advice Wolfman, otherwise I would still be trying to figure out why it wouldn't come out. What makes it especially difficult is the lack of detail in the service manual and all the documentation I could find on the internet about this particular pump.

 

[Dronez]

Ok I got the pump back from the overhaul shop, he also had to salvage some of the injectors. Now I have it all back together and it still wont start. I have tried bleeding the lines at the pump and the injectors. I get a little out of them but seems to be steady. I do get smoke from the exhaust which I think is raw fuel? The original problem was water in the fuel so I'm wondering how much further the damage could be? I took the valve cover off and everything appears to be clean and moving the way they should. I'm scratching my head about now. Any suggestions would be greatly appreciated.

 

[ShaunRH]

I hate to ask, but did you re-time the engine now that you had the pump out of it and rebuilt?

Out of time = no start or you don't WANT it to start... (as in KABOOM!)

Safety tip: keep an open tin can or something nearby with the air filter off for first restart. If it is slightly out of time in the wrong direction, it can run away on you and if you can't get the fuel shut off in time, stopper the intake with the can it will shut it down!

If you're sure of the timing, and you have the glow plugs getting all toasty, it should start.

 

[North Idaho Wolfman]

Timing is simple, Did you put back the shims that were under the pump?

Did you bleed the entire system? On my B7100 you have to start at the filter and go though every bit.
If there is air trapped at any point it will not run.
Also if there is still any water in the lines or injectors it will not start.

 

[Dronez]

Ok, please excuse my dumbass, I guess I am not getting the concept of "timing" on a diesel. While I had the pump out I did rotate the engine so are you saying now that the timing could be off, meaning the injectors are "firing" at the wrong time?

 

[Dronez]

Timing is simple, Did you put back the shims that were under the pump?

Did you bleed the entire system? On my B7100 you have to start at the filter and go though every bit.
If there is air trapped at any point it will not run.
Also if there is still any water in the lines or injectors it will not start.

Yes, I kept the same shims under the pump. The water is all out of the system. I have bled starting at the pump and then at the injectors. I'm just getting a dribble of fuel when I do the bleed. I will try bleeding again from the filter.

 

[North Idaho Wolfman]

if you put the shims back in then timing is fine, no rotating the engine will not change anything.
With the lines off the injection pump to the injectors, throttle set to high, you should get a little spurt when it is cranking, if it's not it's not getting fuel in or something is amiss, either a linkage is not on right, spring got missed, or stop solenoid is not working properly.

 

[ShaunRH]

Ah, sounds like the pump cam is in the engine then, that makes it easy.

So it's not timing. That's good, no Kaboom!

My father and I, having blown up a large 6 cylinder Cat engine after refurbing the fuel pump and thinking it was a timing issue, I'm all timing freaked out now. (It ended up not being timing but a plugged oil channel that let a piston journal sieze...)

 

[Dronez]

Thanks guys, I think I will remove the #4 injector and Leave it connected to the line. Then I'll crank it to see how it is squirting fuel. While I have the injector out, I'll do a compression test on that cylinder to make sure the water didn't affect anything on the head side. If I get good compression then I will start checking back to the pump to see if maybe I did get something in wrong.