lift pump

[Don Crowther]

Just got back from installing the new lift pump. I think that i have every thing bled. I used the return lines on top of the injectors to bleed the high pressure side. Now the engine will only run for about 5 secs.

Will I have to bleed before the injectors right at the high pressure pump? I've changed the filter because all this started just after an afternoon of racing which saw us with the rail in the water more than once.

I've never had this much trouble bleeding a diesel before.
Does anyone have an ideas why this engine will only run for a short time before it quits?
The fuel tank is full of fresh fuel.
just about at the end of my rope trying to get this figured out.

thanks
Don

 

[Ron20324]

Bleed it a second time. Saw that in a previous post a few weeks ago.

 

[Don Crowther]

Ron
I've bled it 3-5 times (lost count) and it will still only run for a short period. And even then it's hard to start as in long cranking times.
Maybe there's still an air leak some where but there's always fuel at the return lines?
thanks
Don

 

[zeehag]

Ron
I've bled it 3-5 times (lost count) and it will still only run for a short period. And even then it's hard to start as in long cranking times.
Maybe there's still an air leak some where but there's always fuel at the return lines?
thanks
Don

you may have to bleed it at the high presssure side--isnt as easy, but is important---air can get in while replacing the lift pump and neeeds to be removed.....goood luck...~~~~~_/)~~~~~

 

[Don Crowther]

Would the return lines be considered as the HP side? If so I've bled them as well
Don

 

[n624ma]

Don, You need to bleed it everywhere, that is after the lift pump, after the engine mounted filter and after the high pressure pump. It sounds like it's after the high pressure pump that is giving you the last bit of grief.
with the engine cranking to start (Stop knob in the run position) loosen the bolts on the rigid lines to the injectors at the injectors (1/2 turn should be plenty) when you either have fuel with no bubbles or the engine starts tighten them WHILE THE ENGINE IS TURNING !!
I have gotten more free cold beer by doing this last part of the bleeding than you would believe.
If you don't have a copy of the Yanmar operators manual for your engine you should get one. It has perfect, complete directions (with great illustrations) on how to bleed the fuel system.
Hope this helps.

 

[Don Crowther]

Thanks John

The smaller bleed screw on the fuel filter feels like it's striped. So I've ordered another one but it missed the flight last night so I will have to wait another day. Once I've changed that out I will try bleeding from lift pump to the injectors.
I do have a operators manual and the pages are getting worn out!!!
Don

 

[Dan Johnson]

3GM's...

don't have a fitting on the crankshaft end into which to fit a hand crank.

I find it difficult to turn the engine over by hand with the compression levers engaged (engine decompressed)--there's still a lot of friction in the rings/cylinder walls, cam, and bearings of a three cylinder engine!

Don, check the little plastic washer on the smaller Yanmar fuel filter bleed screw--they sometimes get a hairline crack and bleed air back into the system.

 

[Steve Dion]

Don: When we had a GM engine, I used the starter to bleed the engine. Just have someone turn the key while you open/close the bleeders. The "newer" engines are self bleeding, but they also do not have de-compression levers (not good). Once you get her bled out you should be good to go.

PS: This is probably one of the major advantages of the electric pump. I am not sure what happens when you bleed your engine with an electric pump, but you still have air pockets?

 

[Don Crowther]

Were up and running!!!

After changing the fuel filter cannister and bleeding the system again. I found that the injection pump has a small bleed screw as well. Once everything had been bled she started first thing and has never started that well before.

Thanks again everyone for all the help and instruction on bleeding the system.
Don