Oil & Fuel Can't seem to bleed fuel system

[Pilot]

Can\'t seem to bleed fuel system

Tractor is a YM 180. I let the fuel level get too low & when I got on rouogh, sloping ground, she quit & at that angle, the gage read empty.

Not a standard fuel system setup--see the photo.

First, I filled the tank.

I have replaced the large white filter near the top of the firwall and the small filter just in front of the add-on pump, shown down low. I have bled the system at the filter on top and at the injectors. At the injection pump, there are two nuts, one nested on top of the other. The manual just has an arrow pointing to these nuts and says essentially bleed here, but doesn't say which one to loosen. A mechanic warned me not to bleed the pump unless I really knew what I was doing, which I do not.

I can get it to fire up & run for a short while at 2000 rpm, but it runs very rough below 1500.

So, on to the questions:

1. If I loosen the fuel lines at the injectors, do I need to crank it for very long to bleed the system? The book says bleed until fuel comes out--it comes out right away.

2. If I bleed it properly, should it run OK immediately or will it take awhile to get back to normal, i.e., is there maybe a little air still in the system & does it take awhile to clear it out?

3. If I disconnect the fuel line on the injection pump side of this extra pump & crank the engine to test the add-on pump, will I just suck more air into the injection pump? How else to test the pump?

Thanks for your help. Right now, she's stranded in the field & this is my second day of fussing with it.

 

[Bob_Skurka]

Re: Can\'t seem to bleed fuel system

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I can get it to fire up & run for a short while at 2000 rpm, but it runs very rough below 1500. )</font>

I've bled several diesel engines and all have run rough right after the bleed. My suggestion is to run the engine for about 10 minutes, there is still some air in there somewhere. Running the engine will get the air out, it will run rough for a little while then it should get smooth sounding, that will be when the air is out.

Usually there is a correct sequence on what to loosen first. Generally you'd start at the fuel source and work toward your injectors. Should be in your owners manual?!?

 

[Pilot]

Re: Can\'t seem to bleed fuel system

Got it fixed!!!

Talked to the mechanic at Fischers Mill (near Portland, OR). Great guys. They told me which nut on the injection pump to loosen to bleed (the small one at the end of the fuel line), suggested I check the fuse for the extra fuel pump (duh! I should have thought of that), feel the pump with the ignition on since I couldn't hear it run, and as a last resort, pull the line between the two pumps & check for flow with the ignition on.

Checked fuses--all good.
Felt pump with ignition on--it vibrated!
Loosened the nut to bleed the injection pump, but ran the extra pump and that did it! It bled lots of air for about 2 minutes, then stopped bubbling.

Then it fired up, ran a little rough at first, then smoothed out & ran OK. Yea! I've been fussing with this for 2 days.