Mep80Xa injector pump leak

[Josephml21]

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 side.

I've thought and tried just about everything I can think of so now I'm here looking for any insight. The leak appears to be coming from somewhere around the base of the IP and the block.

I did notice that when I blew air (from my mouth not compressed air) through the low pressure inlet it was leaking down to the bottom half where the spring and IP pushrod is. I've also noticed that my oil level is rising and it seems thinner leading me to believe that fuel is leaking down via this passage.

When I had the IP apart I looked like the only thing that is stopping fuel from leaking down would be the tight tolerances. Anyone heard of these things eventually wearing out?

 

[Ray70]

Your oil level rising is a sure sign that you are leaking fuel into the crankcase, but other than damage or a crack near the fuel inlet, I don't know how you would be getting that fuel on the outside of the block.
I believe you are correct as far as the tolerances being the only "seal" internally around the plunger, but that being worn should only allow a leak into the crankcase, not externally, so possibly there are 2 issues.
How many hours do you have on the machine and is it only one metering pump leaking or all of them?
Also, in the picture it looks like the pump is sitting up off the block and not tightened down, but that still doesn't explain the fuel leak.
Maybe you could start by trying to clean it all off, drying it and just run the pump to see if the fuel leak comes back with just the pressure from the transfer pump, if not then proceed to check it again while running.

 

[Guyfang]

Something from the picture just is not right in my head. Yeah, maybe the IP is not far enough down. Are you sure that the thrust cup and the TAPPET,ENGINE POPPET are in right? Something seems odd.

 

[Josephml21]

Something from the picture just is not right in my head. Yeah, maybe the IP is not far enough down. Are you sure that the thrust cup and the TAPPET,ENGINE POPPET are in right? Something seems odd.

Your oil level rising is a sure sign that you are leaking fuel into the crankcase, but other than damage or a crack near the fuel inlet, I don't know how you would be getting that fuel on the outside of the block.
I believe you are correct as far as the tolerances being the only "seal" internally around the plunger, but that being worn should only allow a leak into the crankcase, not externally, so possibly there are 2 issues.
How many hours do you have on the machine and is it only one metering pump leaking or all of them?
Also, in the picture it looks like the pump is sitting up off the block and not tightened down, but that still doesn't explain the fuel leak.
Maybe you could start by trying to clean it all off, drying it and just run the pump to see if the fuel leak comes back with just the pressure from the transfer pump, if not then proceed to check it again while running.

The fuel leak was around the IP inlet fitting where the low pressure hose connects. I had a guy run a bead of weld around it and it stopped. I'll get pics up in a few days.

Once I got it all back together I gave it a test run to check for leaks and it ran fine for a few minutes then sputtered out. Water separator was full. Once I solved that issue it runs but the engine won't run under a load. I don't know what is going on anymore I'm just gonna have to start back at square one work the problem.

And to answer the questions everything looks and feels in place. I only remove one IP at a time and never had to wrestle out or in an IP. It was only the one that was leaking. And the set has about 2600hrs on it. It's been mine the whole time and has always ran fine. Im probably just overlooking something in regards to the engine not wanting a load on it.

 

[Josephml21]

The plot thickens. So I decided to pull the other IP and disassemble it to compare because prior to this I've only disassembled the leaking IP.

I've laid out the two, so the IP on the right is the untouched one. It has two extra parts that the other one does not. I've also attach a pic of where it was leaking from and the weld job that stopped the leak.

Can anyone that has experience with these tell me what the correct amount of washers/rings is. The TM does not go in depth (exploded view) for the IP's.

Additionally anyone know where I could source these missing parts? I've already found a supplier for the whole IP but I really don't feel like buying a whole new part when this one is still serviceable.

Thanks

 

[uniquify]

There are at least 2 different manufacturers that make these metering pumps with similar but slightly different designs.
Do both of yours have the same part # stamped on them? I can't quite tell from the pictures.

 

[Josephml21]

There are at least 2 different manufacturers that make these metering pumps with similar but slightly different designs.
Do both of yours have the same part # stamped on them? I can't quite tell from the pictures.

I everything stamped on the housings match exactly. The LP part number, a TPF# and the delphi-II markings are all the same.

 

[uniquify]

Here is some part number info for the injection metering pumps for the Lister-Petter LPW2 & LPW4 (aka Cummins Onan DN2M & DN4M):

Lister-Petter Part#	OEM	OEM Part#
751-41173	Stanadyne	PF70/31466
751-41174A	Delphi	TPF1Q070T3502

Here's a picture of the guts of the Stanadyne version:

 

[uniquify]

Looks like you have the Delphi version, so your internals may be different than my picture above.
Sorry, I don't have any of the Delphi's on my MEPs.

 

[Josephml21]

Looks like you have the Delphi version, so yours may be different.

Yeah I got two delphi's. I guess tonight on the midnight shift I'm going to starts crawling the web to find a parts supplier for these guys.

 

[Guyfang]

Whats the cost of two new IP's? I would never feel good about using something someone else screwed up. And the welded of in any case.

 

[Josephml21]

Whats the cost of two new IP's? I would never feel good about using something someone else screwed up. And the welded of in any case.

$315 US a piece plus me having to re-time two brand new pumps.

 

[Guyfang]

Re-time? What do you need to re-time anything for? You lost me there.

 

[Josephml21]

Re-time? What do you need to re-time anything for? You lost me there.

I was assuming that because you are starting with new parts you would have to reshim the IP since the tolerances have changed.

 

[Guyfang]

Maybe you need to read the -24 TM. There is a procedure on how to do that. You can also send @Ray70 a PM and ask him. He is really very good at that. Or look back at one of his threads where he writes about the procedure.

 

[Ray70]

Here are my thoughts:
In the past we had determined there is a mistake in the TM where is calls the "X" dimension 2.02", that is an error. X should be 2.20", however, experience has shown me that when working on a motor with unknown pump shim requirements, putting 2 black shims under the pump and pushing the fuel inlet all the way against the pushrod tube seems to work every time.
In your case when replacing an existing pump I would use the same shims as you have now , push the inlet against the pushrod tube and call it a day!
You are correct in that a new pump = new clearances but I've found that the shim thickness really is not that critical to engine performance.

 

[Josephml21]

Here are my thoughts:
In the past we had determined there is a mistake in the TM where is calls the "X" dimension 2.02", that is an error. X should be 2.20", however, experience has shown me that when working on a motor with unknown pump shim requirements, putting 2 black shims under the pump and pushing the fuel inlet all the way against the pushrod tube seems to work every time.
In your case when replacing an existing pump I would use the same shims as you have now , push the inlet against the pushrod tube and call it a day!
You are correct in that a new pump = new clearances but I've found that the shim thickness really is not that critical to engine performance.

Thanks for clearing that up, I was concerned that it would be a pain in the butt to get the shim thickness correct

 

[Josephml21]

Here are my thoughts:
In the past we had determined there is a mistake in the TM where is calls the "X" dimension 2.02", that is an error. X should be 2.20", however, experience has shown me that when working on a motor with unknown pump shim requirements, putting 2 black shims under the pump and pushing the fuel inlet all the way against the pushrod tube seems to work every time.
In your case when replacing an existing pump I would use the same shims as you have now , push the inlet against the pushrod tube and call it a day!
You are correct in that a new pump = new clearances but I've found that the shim thickness really is not that critical to engine performance.

I should have asked but I didn't think about it until now. You can hit a pushrod tube going in both directions. Did you turn the IP clockwise or counterclockwise to hit the pushrod tube?

 

[Ray70]

Counter clockwise. touch the tube to the metering pump's right side.

 

[Josephml21]

Counter clockwise. touch the tube to the metering pump's right side.

Perfect, I've also noticed that the set runs smoother turning them that way. Thanks again Ray.