New to me - MEP-003A

[Mr4btTahoe]

FINALLY had some time to get out and work on the genny today. Its been a crazy few weeks as the company I work for is in the middle of a merger that all but wrapped up friday.

Anyways, hooked the batteries back up and toyed around a bit. Now that the fuel cut solenoid linkage is not bound up, the solenoid is definitely moving. Not sure if it's moving far enough.. but it is moving. Still no fuel out of the injection pump so I decided to dig into the pump a bit. Pulled the delivery valve holder/assembly and found the plunger to be frozen. I lightly tapped the plunger and it retracted so I hosed it down with penetrating oil.. bumped the start switch and it pushed back out and stuck. I repeated the process 20 or so times until the plunger moved freely while cranking. I reassembled the pump in reverse order.

After reassembly, I loosened an injector feed at the pump body and cranked the engine over and now I'm getting fuel out of the pump (before, there was nothing).

I snugged the line back up and hit the pre-heaters for 60 seconds as per the manual and cranked it over. Nothing. Very little smoke out of the pipe (more likely just moisture).

Where to go from here... ideas?

 

[Mr4btTahoe]

Also... I keep reading about a spacer that should be under the delivery valve holder but mine didn't have a spacer. All that I found was a spring and the metal piece under the spring that sits on the plunger. No plastic spacer.

Does anyone have a picture of the spacer and just how critical is the spacer?

 

[jamawieb]

FINALLY had some time to get out and work on the genny today. Its been a crazy few weeks as the company I work for is in the middle of a merger that all but wrapped up friday.

Anyways, hooked the batteries back up and toyed around a bit. Now that the fuel cut solenoid linkage is not bound up, the solenoid is definitely moving. Not sure if it's moving far enough.. but it is moving. Still no fuel out of the injection pump so I decided to dig into the pump a bit. Pulled the delivery valve holder/assembly and found the plunger to be frozen. I lightly tapped the plunger and it retracted so I hosed it down with penetrating oil.. bumped the start switch and it pushed back out and stuck. I repeated the process 20 or so times until the plunger moved freely while cranking. I reassembled the pump in reverse order.

After reassembly, I loosened an injector feed at the pump body and cranked the engine over and now I'm getting fuel out of the pump (before, there was nothing).

I snugged the line back up and hit the pre-heaters for 60 seconds as per the manual and cranked it over. Nothing. Very little smoke out of the pipe (more likely just moisture).

Where to go from here... ideas?

Unfortunately, if you didn't check the plunger before the initial start up then it probably broke the plunger guide inside. If the plunger was at the lowest position when you turned it over, it shoved the plunger up and then stuck in the highest position, which usually breaks the guide. You'll need to take the pump out and apart to see if the plunger guide is broken. When the plunger guide breaks, the plunger will move in and out but it will never be in the correct position to send fuel to the correct injector, at the correct time. You may see it coming out an injector port but its not coming out at the correct time.

 

[jamawieb]

Also... I keep reading about a spacer that should be under the delivery valve holder but mine didn't have a spacer. All that I found was a spring and the metal piece under the spring that sits on the plunger. No plastic spacer.

Does anyone have a picture of the spacer and just how critical is the spacer?

It's not that important, its a little plastic gasket that fits around the valve assembly under the spring. It's orange when new but after they have been in the motors for years, they turn a brown color. Check out the part break down on the attachment. Its number 5 on the head assembly (page 3) and the plunger guide is number 11 on the gear breakdown (page 4)
https://cdn.greenmountaingenerators...etering-MEP002A-MEP003A-50-2-4A-80A-9540A.pdf

 

[Mr4btTahoe]

I've heard in some cases that it being missing can cause the engine not to start (not build enough pressure to pop the injectors).

I'm not getting hardly any smoke (same as I was with the plunger frozen). I would think that even if timing was all over the place, if the injectors were opening, I'd be getting some white smoke.

I also noticed that the spring looked a bit rough. One of the coils on the end was a bit worn and bent slightly. Debating on ordering a full seal kit which comes with the spacer collar or just order the collar and spring for now.

I very well may have to pull the pump apart for a full re-seal and replacement of any damaged parts but want to make sure before I do it.

 

[Mr4btTahoe]

Ok.. I've got the re-seal kit, delivery valve spring, and plunger guide in my shopping cart ready to go... Any other common failure items to order while I'm at it?

Suck part is I'm at $145 and I could have snagged a reman pump for just over $200 last week. Blah.

 

[Guyfang]

Your making progress partner, making progress.

Have you ever done anything like an IP removal? Have you read the -34 manual and understand what you read? The IP removal, repair and re installation is not all that hard. But its also easy to screw up. You just need to take your time. If this procedure is not new to you, then please disregard.

 

[Mr4btTahoe]

No problem.. I've rebuilt a couple pumps so it isn't all that new to me but I'm still in a debate on whether or not I want to pull the pump and go through it or just try and replace the few parts I know are missing/damaged without removing the pump.

I haven't looked at the manual yet as far as procedure for pulling the pump.. but I'd assume that it needs to come off with #1 at TDC on compression and with the other pumps I've been through, there has always been a way to lock the pump at that same setting. I'll do some digging in the book and see if it'll be worth the hassle.

 

[Guyfang]

You should not have a problem then.

 

[Mr4btTahoe]

Ordered everything. Thanks to the MEP Wiki.. I found the phone number for Ambac and got the parts I needed for less then half of what GMG wanted for them. Ordered the delivery valve spring, reseal kit, and the plunger guide (just in case).

They'll be here this week.

 

[rosie]

Just a suggestion about drying the fuel tank; we have found what works really well for us is to use a leaf blower. Place the nozzle/port into the fuel filling cavity, wedge it between two items, i.e. a rock or stump, and on the leaf blower end, a cooler full of beer. If the leaf blower starts to move backwards while running, replenish the cooler. You will be amazed at how quickly the tank will dry out, especially if you open up as many ports as possible to allow the air to travel through the tank and exhaust.

Our two cents; hope this is helpful.

Regards, "rosie"

 

[Jetred]

I used one of the $20 shop-vac’s from Home Depot. It’s comes as a motor and hose, set the motor on a 5 gallon bucket. The bucket becomes the housing for the shop-vac.

Swirled water in the tank from the garden hose (Had a lot of “moon dust” in the bottom of the tank) to keep the sand suspended in the water. That little vac sucked out the water fast, I was impressed. Think I did it three times and there wasn’t any sign of the sand left. Moved the hose end at the motor to the blower fitting. Left the hose in the fill port for two hours. Hose is only about 2” O.D. Plenty of room for the air to exhaust around it.

I did did buy a second shop-vac just for that project. Didn’t want to use it in my truck or in the house cleaning up and leave the smell of diesel behind. Handy little things, only downside is the four feet long hose. I learned about them watching electricians pull strings long distances through conduit.

 

[Mr4btTahoe]

Still waiting on IP parts. USPS apparently lost my shipment from Ambac so they are overnighting the parts on their dime. Said I could keep the others if they ever show up. Score for spare IP parts. Lol.

 

[Mr4btTahoe]

Rain is gone and sun is out.. so got to work on it again for a bit.

Pulled the delivery valve back out and cleaned the remnants of the little spacer (all that was left was few little black chunks) out and installed the new spacer. Installed the new DV spring and put it back together. No dice.

I've got the plunger guide and the rest of the rebuild kit so the pump is going to come off later tonight and hopefully I'll get time this week to open it up.

Right now, I'm looking for a guide on doing this. Should be straight forward but I don't like going in blind so to speak.

 

[Mr4btTahoe]

Said screw it and bit the bullet. One of the injector feeds was under pressure. The others were dry. I'm going to say the plunger guide is fried. We'll see.



I'll rebuilt it tomorrow and go from there. I also ordered new glow plugs and manifold heaters. I noticed today that the GP harness is shot so I'll rebuild that while I'm there. Hopefully I get to hear it run for a few seconds sometime this week. Still need to order a throttle cable.. but want to hear it fire off first.

More to come. I'll take pictures while going through the pump.

 

[Guyfang]

I am kinda new to this stuff. What's a GP harnes?

 

[Mr4btTahoe]

I am kinda new to this stuff. What's a GP harnes?

Jjust short for glow plug. The wire ends are broke off on a few. Figure I'll cut it all back to good wire and replace it all while I'm replacing the plugs.

 

[jamawieb]

Rain is gone and sun is out.. so got to work on it again for a bit.

Pulled the delivery valve back out and cleaned the remnants of the little spacer (all that was left was few little black chunks) out and installed the new spacer. Installed the new DV spring and put it back together. No dice.

I've got the plunger guide and the rest of the rebuild kit so the pump is going to come off later tonight and hopefully I'll get time this week to open it up.

Right now, I'm looking for a guide on doing this. Should be straight forward but I don't like going in blind so to speak.

1) take the throttle linkage out (take the flat head screws out and then it slides out.

2) back the inlet and outlet adapters out or take them out completely

3) take the 4 allen screws off the housing and then push the pump out of the housing.

4) take the big c-clip off and separate the pump, you'll have the gear set in one hand and the ports for the injectors in the other. The gear set will have the plunger sticking out of it and if you look at the end, that the plunger is protruding from, you'll see a flat piece, that is the plunger guide. The plunger guide will be broken in half or it will be rounded off, where the plunger will just spin.

5) take the cap off the end of the gear set. When you take the cap off you'll see the button under it

6) there is a little clip that holds the button in place that has to be removed. I use a little pick to pick it out but be careful because it will fly off and you'll never find it.

7) after you remove the button. You'll see the end of the plunger under the spring. It's held in place with 2 half circles (best way I know how to describe), you have to depress the spring and get the half circles out. This is the hardest part of the whole thing. I have a pair of need nose vice grips that I cut the nose off of to make them flat. Then set them far enough apart to go around the plunger so I can put the plunger on a hard surface (Like a desk) and depress the spring with the vice grips to get the half circles out.


remove the spring, plunger and guide.

Everything is reverse.

 

[Mr4btTahoe]

That'll certainly help. I'll see if I can take pics of each "step" and perhaps put them together for others to find later.

 

[Mr4btTahoe]

Got it done. If I can, I'll get it reinstalled tonight..

I put together a post with detailed pics of the rebuild process. I posted it here...
https://www.steelsoldiers.com/showthread.php?183913-Ambac-M-50-Rebuild-w-pics&p=2181691#post2181691

It was very simple. I noticed when I pulled the pump, it would turn freely but wasn't easy or smooth. Now, it spins very smooth and easy. Throttle also moves very freely. I would highly suggest going through the pump for anyone that has a unit that's been sitting for a long period. Even if you can get it running, I would. My plunger guide wasn't broken and could probably have ran but it was very loose and cracked. It wouldn't have lasted long and timing would have been all over the place.

Anyways, hopefully more to come soon!