MEP-803 fuel pump Length discrepancy

[loosegravel]

Just some more thoughts to hopefully ease your mind. I know that I've mixed up the IP shims on a unit or two, and they still ran. They might not have run as efficient as they should, but none the less they still ran. By swapping those IP's around and cranking the engine over, you should be able to determine if you have a flat cam lobe or not. Hopefully not. The other thing is compression. We see piston ring seizure on occasion from rainwater intrusion, condensation in the combustion chambers, or whatever. While you're cranking this engine over with a good, fully charged set of batteries how does it sound? It should be a consistent sound with no change or "skipping". A skipping sound would indicate low compression in one of more cylinders. (That could also mean a valve issue in the cylinder head on one or more cylinders) When you get this engine running, another test for engine integrity is to remove the engine oil fill cap down by the dipstick. With the engine running you should be able to lay a piece of paper over that hole and it should hold it there from vacuum. If it blows it off, that's an indication of too much crankcase blow-by.

 

[loosegravel]

The fuel pumps work ok, when I press the spring, they pump out fuel.

curiosity got the best of me lol, took out one of the known good pumps from #3, zip tied that shim pack together and measured it. 1 and 2 are no where close to this measurement. Somebody definitely messed with the shims. Gonna get a few new sets and make 1 and 2 the same thickness.

am I correct in assuming that since the shims are messed up on 1 and 2, this is causing over fueling on those cylinders ?

The only variable that I can think of is cam lobe height. I don't know why else the shim thickness would be so far off. But for now, we're just trying to figure out why you're not getting any fuel out of #2. So, maybe write down what shim thickness that you originally had under each IP. Then, you can move them around if you want to try that, but ultimately you can also put them back the way that they were. Let's figure out why #2 isn't pumping any fuel. Swap IP's around and see if the problem changes holes.

 

[loosegravel]

I wish these engines had compression releases to take the strain off of the starter and the batteries while cranking them over to check things like this. But they don't. Hopefully you have a means of keeping the batteries charged up while you're doing this stuff. Also, don't use the dead crank switch if you're testing for fuel delivery. You definitely need the electric lift pump running while you're cranking the engine over.

 

[Guyfang]

Shims do not have anything to do with the amount of fuel coming out of the IP.

 

[uniquify]

Looks like these pumps are a Delphi ? Maybe there was another manufacturer they used ?

Here's a link to a post in different thread with some metering pump part numbers:

Mep80Xa injector pump leak

As the title says I have an injector pump leaking fuel. I've ripped the whole thing apart, cleaned it and replaced the o-ring on the high pressure side. I double checked the fuel line and when I put in all back together today I replaced the hose clamp with a new crimp clamp on the low pressure...

www.steelsoldiers.com

 

[Ray70]

@Ray70

Ray, you ever seen this?

Yes, the TM has a typo! It should be about 2.250" I think the TM should have said 2.2" not 2.02"

 

[Sidis8]

Yes, the TM has a typo! It should be about 2.250" I think the TM should have said 2.2" not 2.02"

Cool, figured it was a typo. Glad to confirm. Thank you

 

[Light in the Dark]

Shims do not have anything to do with the amount of fuel coming out of the IP.

Per the Lister Petter Alpha series workshop manual:

 

[Light in the Dark]

Yes, the TM has a typo! It should be about 2.250" I think the TM should have said 2.2" not 2.02"

Which was probably picked up from a typo from L-P. From their manual on this engine series:

 

[loosegravel]

Which was probably picked up from a typo from L-P. From their manual on this engine series:

View attachment 891854

It’s pretty involved to get those IP’s set up correctly isn’t it?

 

[DieselAddict]

Looks like how we degree in a cam on a race engine.

 

[Light in the Dark]

Yeah it is at the factory, but those steps should not need to be taken by an end user if just replacing worn items with new. Just a matter of paying attention to positions of items when removed. I assume due to the block being cast iron, this is just a low tech approach to tolerance variations at the deck level.

 

[Sidis8]

Hey guys

so finally did a compression test yesterday, # 4 was around 450 psi, 1,2 and 3, not even registering.

poured some oil into each cylinder and let it sit over night.

holy crap, every cylinder almost at 500 psi right now.


I couldn’t find a compression adapter for this engine, so made 1, basically a 17 mm rod with a 1/8 npt port to connect to a gauge, worked real well.

real glad the compression came back, was ready to tear the whole damn thing apart lol

 

[loosegravel]

Hey guys

so finally did a compression test yesterday, # 4 was around 450 psi, 1,2 and 3, not even registering.

poured some oil into each cylinder and let it sit over night.

holy crap, every cylinder almost at 500 psi right now.


I couldn’t find a compression adapter for this engine, so made 1, basically a 17 mm rod with a 1/8 npt port to connect to a gauge, worked real well.

real glad the compression came back, was ready to tear the whole damn thing apart lol

That’s good news right there! Your persistence and determination is going to pay off. Some of these units need more than others to get them up and running. It appears that you will have a running unit before too long. Just wondering, did you ever swap holes with the IP’s to see if the problem was actually in the pump and not a camshaft issue?

 

[Sidis8]

That’s good news right there! Your persistence and determination is going to pay off. Some of these units need more than others to get them up and running. It appears that you will have a running unit before too long. Just wondering, did you ever swap holes with the IP’s to see if the problem was actually in the pump and not a camshaft issue?

I think it’s a faulty fuel pump, #3 fuel pump in 1 and 2 spot causes fuel to come out of it while cranking the engine.

 

[loosegravel]

I think it’s a faulty fuel pump, #3 fuel pump in 1 and 2 spot causes fuel to come out of it while cranking the engine.

Ok, no flat cam lobe here! That’s good. I haven’t seen or heard of any cam issues yet on these Lister Petter engines. One of the other members here has had issues with the oil pump relief valve sticking. It’s an interesting scenario. Because the oil pressure has no place to go, it pumps up the hydraulic valve lifters until they’re solid, and then the valves won’t close all of the way causing no compression. I’m only mentioning it here because you mentioned that you had low or no compression on 3 cylinders. Glad that the oil that you squirted into the cylinders seems to have solved that problem.

 

[Sidis8]

Ok, no flat cam lobe here! That’s good. I haven’t seen or heard of any cam issues yet on these Lister Petter engines. One of the other members here has had issues with the oil pump relief valve sticking. It’s an interesting scenario. Because the oil pressure has no place to go, it pumps up the hydraulic valve lifters until they’re solid, and then the valves won’t close all of the way causing no compression. I’m only mentioning it here because you mentioned that you had low or no compression on 3 cylinders. Glad that the oil that you squirted into the cylinders seems to have solved that problem.

Hopefully it was just stuck rings and the oil got them loose and they’ll behave from now on.

now to deal with all the wires chewed by the rats that had a palace set up in there lol.

 

[Light in the Dark]

Take a photo, someone may have wires available so you don't have to reinvent the wheel. Glad to see it was a ring issue .

 

[Sidis8]

Take a photo, someone may have wires available so you don't have to reinvent the wheel. Glad to see it was a ring issue .

these rats or whatever it was really made a mess of things.

The worst part is the smell, still trying to air it out.

I really hit the jackpot with this unit

 

[Ray70]

I couldn’t find a compression adapter for this engine, so made 1, basically a 17 mm rod with a 1/8 npt port to connect to a gauge, worked real well.

Nice work, your adapter looks exactly like what I made too. Pretty much a "Dummy" injector with a threaded hole for a compression gage.
Only difference is that I recessed an O-Ring into the face to seal it to the head, rather than having to crank down the clamp to seal it against the copper washer. Made one for the 802/803 and similar thing just much fatter for the 002/003.