MEP 802a ran out of fuel, is hard starting now, running on 1 cylinder?

[BadMastard]

Hello everyone, been off the board for a while. Now I'm enjoying my a3 with one less axle and a dump bed! Yay. But that's not why I'm posting.

I have a MEP 802a that had very low hours. I lent it to my neighbor for their emergency and they ran 180 hours on it. Then, they forgot to put diesel in it, and it ran dry. It wouldn't start, so I went through the manuals and performed all the tests. even made sure the lines were primed, which is more painful than you'd expect.

I got to removing one of the injectors to test it, and cranked the motor with the injector loose in the hole. Guess what? it started running.

I tightened it back up, and it still runs, but poorly. I think it may be on one cylinder, and I think it might be the one I just rattled around.

Has anyone else had a run out of fuel incident similar? I think the injectors were locked, and knocking one around fixed that one. I'll go loosen the other one, but I didn't see anything in the TM's that said it should need maintenance after running out? And how critical is replacing the crush washer at the injector?

Comments? Ideas? etc?

Jerry

 

[Ray70]

How sure are you that you got all the air out of the lines? Definitely sounds like some air in the fuel lines still.

Maybe you should try cracking the line at the injector again while its running and see if you get any more air out of the line to the dead cyl.??
Can't see what damage running out of fuel would cause, but I've never worked on an 802a either....

 

[Isaac-1]

The copper crush washers on diesel injectors should be re-annealed before reuse ( hang them on a steel wire and heat them to a dull red with a propane torch, then let them air cool) otherwise they generally don't need to be replaced most of the time. As the others have said it sounds like you have air in the lines still, how long did you let it run on one cylinder, often diesels will clear up after a few minutes once the air works its way out.

p.s. be careful cracking the line to let the air out, diesel is under considerable pressure and can be injected under your skin, good gloves and wrapping the fitting in a shop towel makes this process safer. Diesel injected under skin is at a minimum very painful and at worse can require amputation or even cause death.

 

[BadMastard]

Thanks for the advice. I ran it about an hour, and only noticed poor performance under load, say 3000 watts. Startup is way more difficult than it was, before I could turn the switch, wait 1 second and release. Ran like a happy kitten. Now I have to hold it 10 seconds or so, and it runs relatively ok until under load. Great hint on the copper washers. I can certainly burn things to make them better.

 

[BadMastard]

Update and more questions... So I cracked the Pump lines and when I took off one, fuel starts flowing engine starts dragging. Plug it back in? All is back to running poorly, but running. Crack the second line, fuel barely dribbles. Ideas?

 

[pclausen]

Could it be that the 2nd injector pump is not properly primed and/or got somewhat "stuck" when it ran out of fuel? Perhaps taking it out and letting it soak in kerosene overnight might do it some good.

 

[m-35tom]

remove the line from the top of the pump and then remove the top section, the next nut. use some 2+2 gum cutter and clean the plunger. the injection system is self priming so you probably have a stuck pump.

 

[BadMastard]

Update to the thread. So, I've found some very interesting things. I'm about to take apart the injector pumps on the generator after finding that sometimes just sitting makes them stop pumping fuel. loosening the retaining bolt and turning it over usually get's it running in seconds, but until then, not starting. I am taking M-35tom's advice and cleaning them up to see how it does. I'll update, with pictures, next.

 

[m-35tom]

be very careful removing the delivery valve from top of pump while in engine, there are several small parts, spring holder, spring, valve, valve seat, and 1 or 2 shims. with a mirror you can see the plunger rotate when you move the shutoff control. do not crank engine with delivery valve out, it may push the pump cylinder out and that would not be good. do you know that rotating the pump body is what sets the fuel delivery rate? once loosened if it moved, one cylinder could be getting more fuel than the other which could lead to hard starting and low power. use a temp gun on the exhaust area of head, should be same temp.

 

[BadMastard]

Hey Tom and team,

So, it's been cold out, and the generator has sat still for a bit. I'm back working on it.

More to the story. It started right up after a week or two of sitting. then when we shut it down after a few hours of use, it won't start again. Exhaust temps about the same. Same problem as before, so I went and checked fuel from the tank to the injection pump. Fuel is getting there. so I removed the left pump, and broke the top down. looked ok, nothing sticking but soaked it a bit anyway. put back together. Same thing. Fuel gets to pump, doesn't come out the top of either injection pump.

I can feel the u shaped lever in the pump hole turn if I move the fuel cutoff manually. seems to be in the right spot.

I tried rotating the pumps slightly within their range to see if helps. Kinda tedious, but not horrible. I just don't see fuel coming off the loosened tops of the injection pump.

ideas?

Jerry

 

[m-35tom]

you cannot just take the lines off and expect fuel. you must then remove the top of the pump and remove the fuel delivery valve. clean everything first and be very careful as there are several small parts and shims. with a mirror look down in each pump, it must rotate with the fuel lever and must pump up and down. do NOT crank it or it may push the cylinder out and it won't go back in. just rotate it slowly by hand with the fan to see what is moving. the center plunger must go up and down, the outer sleeve or cylinder must NOT move up so beware. also with the fuel delivery valve out fuel may flow out with the pump on.

if you have removed either pump, they may not go back in correctly until you back off the low speed adjustment quite a lot.

 

[BadMastard]

Thanks Tom, I didn't explain that I did take off the top and clean them up. They looked **** near brand new, so that wasn't where it was sticking.

Ok, I pulled one of the injection pumps out, and moved the fuel stop lever by hand. then I pushed against the lever while it was opening the fuel line and it seems that the pressure was probably insufficient to move the stop lever on the pump, as I compared it to the pressure required to turn it by hand. Would seem to be very very insufficient. I'm about to take off the top of the pump and see if it's moving, but I'm pretty sure my answer is no.

How much force is usually required to operate the stop lever? it seems to be spring loaded, is there a place to adjust the force?

Oh, thank you for the warning on the pumps. they are engaging well in the slot, but I'm thinking it just doesn't have the force to move them.

Any other hints? because a weak spring would explain why it failed to operate sometimes, but ran awesome otherwise.

Again, many thanks. Shame you're one the other side of the continent, you've earned a beer or two from me.

 

[m-35tom]

there is no 'spring' involved. the pin rotates the plunger and it must rotate very easily. if it will turn at all you are in a good position to use laquer thinner to dissolve the old fuel residue. many other solvents will not do it. just keep it very wet and rotate until it gets really free. again with the top off, the cylinder can just fall out the top so maybe just screw the empty top back in to hold it.