MEP 802A No start. very little fuel through pump.

[DACollins]

Hi All,
I'm relatively new to the site. I've posted a few things so I'm a little green here. Have worked on mechanical things for many years, just not any category consistently.
That being said, I recently acquired this 802A from a govt auction. 28 hrs, looks relatively unused. Brought it home, new 15W-40, filter, coolant and batteries. The other filters looked like they'd never been used, so I kept them. Plugged the drilled hole in the tank and put 5 gallons of fresh ULSD fuel in the tank. Turned it to prime, elecc. pump runs, squirts fuel at the pump supply lines. Won't start. When cranking only a small amount of fuel comes out at the top of the #1 pump, nothing on #2. Removed both pumps (*) and disassembled and cleaned. #2 plunger was stuck until polished and lubed. Reassembled. Now more fuel at #1 injector line, nothing @ #2. (Same condition as before disassembly)

Also, when cranking, the exhaust flap moves quite well, but there's a large amount of air and an oil mist that moves in and out of the dipstick hole if the stick were removed. Normal? Oil level slightly too high?

I'm baffled.

(*) Also, If both pumps are removed at the same time, yet separated and reinstalled with shims/ gaskets in same order, is the only other issue making sure the pin from the bottom of the pump is engaged into the governor rack? Or have I missed something about fuel control? I certainly don't want a run-away.

Any help would be appreciated. This one has me stumped. I've been able to start many things over the years until this little devil.

Thanks in advance!

 

[Scoobyshep]

Fuel valve set to tank?

Sent from my SM-G950U using Tapatalk

 

[Ray70]

It's difficult to say as far as the oil mist and crankcase pressure, without seeing it in person, but keep in mind, both pistons move up and down in unison not 180* apart, so pulsating air is somewhat normal. If the motor sounds like it is cranking too freely ( lack of compression resistance and sound ) you could have valve sealing issues BUT.... first you should figure out the fuel problem.
If you removed both pumps together you do need to ensure both pins are correctly into the rack when reassembling.
Sometimes it can be difficult to get back together when both have been removed, but it can be done.
You have to manually push the rack towards the fan then get 1 pump in place. Keep in mind the clearance inside is very tight, so the pin will hit on the underside of the block surface almost until the clamp is fully tightened, so don't feel as though something is wrong if the fuel rack appears stuck until the pump is fully inserted.
Once you get decent fuel pulses from both pumps we can move on.
While the pumps were out were you able to get both pump plungers and throttle pins moving freely?
Once they are installed you can feel resistance in the fuel shut off lever if they are moving correctly.

 

[DACollins]

I believe so, when I turn on the prime it sprays fuel out. Are you referring to the S1 switch? I don't see any other fuel switch?

 

[Guyfang]

While I was writing, Ray took the words right out of my mouth/fingers. Next time, only remove one pump at a time. Its a lot easier to get them back in right that way.

If you got the pumps good and clean, there is a way to get a feeling as to if the pumps are seated right. Loosen up the clamps that hold the pumps in the engine. Then manually move the "throttle linkage", back and forth. At the same time, hold the first pump in your hand, The pump should rotate in cadence with your moving the linkage. If not, then you have them in wrong.

 

[DACollins]

It's difficult to say as far as the oil mist and crankcase pressure, without seeing it in person, but keep in mind, both pistons move up and down in unison not 180* apart, so pulsating air is somewhat normal. If the motor sounds like it is cranking too freely ( lack of compression resistance and sound ) you could have valve sealing issues BUT.... first you should figure out the fuel problem.
If you removed both pumps together you do need to ensure both pins are correctly into the rack when reassembling.
Sometimes it can be difficult to get back together when both have been removed, but it can be done.
You have to manually push the rack towards the fan then get 1 pump in place. Keep in mind the clearance inside is very tight, so the pin will hit on the underside of the block surface almost until the clamp is fully tightened, so don't feel as though something is wrong if the fuel rack appears stuck until the pump is fully inserted.
Once you get decent fuel pulses from both pumps we can move on.
While the pumps were out were you able to get both pump plungers and throttle pins moving freely?
Once they are installed you can feel resistance in the fuel shut off lever if they are moving correctly.

I didn't realize the cylinders weren't opposite. That's a bit of a relief.
I did get the plungers and pins moving freely. The #2 plunger was stuck compressed. It was not compressed again when I removed the pump the second time.
I'll get to the unit either later this evening or tomorrow and see where we go.
Thank you!

 

[DACollins]

I have removed the metering pumps again and found that the two behave differently when fuel (or in this case, penetrating oil) is supplied to the inlet. With the fuel in the "off" position, the #1 pump does not allow fuel through, while the #2 pump does. This is in contrast to how they behaved when installed originally. I have disassembled #2 again looking for correct alignment and seating. I must be missing something.
Does anyone have a schematic of the metering pumps. I cannot locate one on the Lister Petter site nor in the TM's.
Thanks in advance.

 

[Ray70]

I don't think I've ever seen a schematic for the pumps.

 

[Guyfang]

As far as I know, there is none.

 

[Ray70]

Best thing I've found for the metering pumps is to get a gallon of the "soaking style" carburator cleaner and soak them for a couple days, that usually fe=rees everything up, but if you disassembled them and reassembled incorrectly you'll have to take it apart again.
Unfortunately the few I've had apart, I don't remember enough about them to try to help you fix them.

 

[uniquify]

Does anyone have a schematic of the metering pumps. I cannot locate one on the Lister Petter site nor in the TM's.
Thanks in advance.

I don't have a schematic, but I took a bunch of pictures when I had the top half of a stuck pump apart a few months back.

Check out post #21 here:

Mep-803a motor locking up at 0 and 180deg

Here's what my stuck pump looked like. The large spring at the bottom is compressed. The fuel lever that fits into the rack couldn't rotate left or right. Took the top off the fuel pump with a 17mm. It's normal right-hand threads. Looking inside, the plunger is the shinier piece in the...

www.steelsoldiers.com

 

[uniquify]

Lister Petter part# is 751-41175.

I think the equivalent Stanadyne part# is PF70/31466.

 

[DACollins]

While I was writing, Ray took the words right out of my mouth/fingers. Next time, only remove one pump at a time. Its a lot easier to get them back in right that way.

If you got the pumps good and clean, there is a way to get a feeling as to if the pumps are seated right. Loosen up the clamps that hold the pumps in the engine. Then manually move the "throttle linkage", back and forth. At the same time, hold the first pump in your hand, The pump should rotate in cadence with your moving the linkage. If not, then you have them in wrong.

I've installed the pumps. Found the TM regarding 'stuck' rack. Adjusted both pumps and #1 allows fuel past when shutoff is in off but prime pump running. #1 does not squirt with injector lines off and cranking engine.
#2 does not allow fuel past when priming, but does squirt when cranking, even with fuel shutoff in off.
I'm hesitant to hook up injector lines and attempt to start as I don't want a runaway.

Thoughts?

Thanks much in advance.

 

[Ray70]

One thing that comes to mind, if the pump itself is good would be a problem with the cup under the pump that rides on the camshaft.
Make sure it isn't either missing or stuck in the bore and not allowing full motion of the pump.
The other thing to do would be to swap the pumps and verify if the problem follows the pump of if it stays with the cylinder.
That will point you towards either a pump issue or something else driving the pump.

 

[DACollins]

thisIt lives! It didn't run away when started, which I am thankful for! It maintains rpm and is spot on the Hz when adjusted.
I do have two questions:
-It shakes quite a bit. I tried to video it, but it looks like it isn't shaking in the video. I can almost hear a bit of a knock. I am familiar with older Lister Petters that move a lot and are noisy. Just want to make sure I'm not missing something?

-The water temp indicates around 180+/-. Seems a bit high? I cannot find a spec in the TMs for operating temp. This just seems a bit odd?

Thank you all!

 

[robertsears1]

My MEP 002a shakes a great deal more than my 003a. Kind of apples to oranges but I think it is more the two cylinder vs four cylinder effect. Both of my 804s run right at 180 degrees.

Robert

 

[kloppk]

The -10 TM table 1 specifies....
Normal Operating Temperature 170-200 °F (77-93 °C)

My 802 runs at 180 +/- when warmed up.

 

[Guyfang]

All military gen sets that are "water cooled" run at 180-200 degrees.

First get everything fixed, then we can try and suggest a few things to look at concerning vibrations. There is not much to be done, but a few things to check.

 

[Ray70]

We're dying to know what the problem ended up being??
Did you have a lift pump issue or something else?

 

[DACollins]

All military gen sets that are "water cooled" run at 180-200 degrees.

First get everything fixed, then we can try and suggest a few things to look at concerning vibrations. There is not much to be done, but a few things to check.

Excellent! It runs at the correct temp. Fires up, quick puff of black smoke and then settles in on the rpm.
Other than checking the vibration, it's ready for a new home!