New to me MEP 002

[redlight]

Greetings,
I have a 002 from the GSA/fire service in western Mass. It was mounted in a 416 trailer when sold. I have now separated the two and have started to work on the generator. I have two new 12 batteries and the unit turns over nicely. I now have some basic questions after downloading the manuals and reading them at a high level review.
· Manuals are for MEP002a- what is the alpha designation for?
· Fuel gets to the IP but not to the injectors. Where should I concentrate my efforts?
· How do I tell if fuel is being returned to the fuel tank?
· Are there used IPs around or who rebuild them?
Thanks in advance. I have rebuilt m38a1's, M37's, ,a M43, and a M151. All gas engines now, I am learning about diesels.

 

[Isaac-1]

Ok, here goes,

1, no idea, but they all seem to be MEP-002a's

2,My guess is a stuck plunger in the pump or a seized pump where you have sheared the drive washer.

3, You should be able to hear it dribbling back into the tank with the switch in the run position before turning it to start, you should also hear the clicking of the electric fuel pumps.

4, Rebuilt Ambac M-50 injection pumps show up fairly often on that big auction site that starts with a e Note there are multiple revision of this injection pump where the guts are very different, but they do interchange.

 

[cuad4u]

As Isaac-1 said new and rebuilt Ambac M-50 IP's are on the "E" auction site right now. The prices are significantly less that what I paid several years ago. My advice is to get one while the price is low. While some on this site claim that rebuilding an IP is something that most anyone can do, I found otherwise. Just pay the $$$ for a new or rebuilt IP and you are good to go for a normal life time.

The new and rebuilt IP's come without the timing "button". Before you install a new or rebuilt IP you MUST remove the "button" from the existing IP and install it in the new IP. This is really an easy thing to do.

There are something like 14 different buttons. The button goes with the engine not with the IP. Any IP you install on your engine must be fitted with the original button or the engine won't run properly......or worse.

 

[Guyfang]

Here's my take on the matter.

1. There was only one type gen set made, and that's the MEP-002A. No need to worry about the A.

2. Isaac could be right. Also, you may have NO button in your IP, because someone else tried to replace the IP, did not know you had to remove the button and now you have none. You need to check. READ THE BOOK before you attempt to pull the IP. If not, you will hate life. Trust me.

3. As per Isaac, yes you should hear it in the tank. Remove the cap and strainer. Also, I would completely remove all lines and fitting to include the electric fuel pumps, and give them a good cleaning. Check to see if the electric pumps run, AND pump fuel, (not always the same thing). Insure that the strainers are in the electric pumps. Put your hand on the AUX fuel system solenoid, and feel if it turns on and off when energized. If you have doubts, then crack lines to see if fuel SHOOTS out. Not dribble.

4. Should you be missing a button, do not jump from the roof, nor eat a pistol. There are kits available with all 14 buttons. In the TM, it explains how you can figure out what button is the right match for your IP/engine. READ THE BOOK. Its not so hard. There is also, in the TM, a passage to explain what to do if for instance you can not read the info on the IP. That info helps you figure out what button is the right one. There is a "general" button that CAN be used, but you should try and get the right one.

A small tip. When you have installed a IP, with button in the set, and it gets fuel to the injectors, but will not start, READ THE BOOK. It will explain that in all probability, your IP is 180 degrees out of time. Simply undo all the lines and stuff, pull the IP out a ways, and turn the engine around until the timing marks line back up, an hook er up!

Get the books. All of them. Read them. This is a darn fine generator, but it helps to be smart about it.

 

[Ray70]

Humm, seems my last post didn't go through, so here goes again...
Ambac has all the schematics and install instructions on their web site.
Its pretty east to remove, rebuild and install these M-50 pumps, assuming no one else messed with the timing or the button.
If you aren't getting any fuel out of the pump, my guess is that the drive washer ( the dogbone) is broken, which is very common on machines if they sit for several years without being run.
If you go with a new or different rebuilt pump you will have to follow the timing instructions and get the appropriate thickness button.
I'm just south of you in RI and have copies of the Ambac stuff if you need it.

 

[redlight]

Thank you all for the information. Like all of us i have several projects ongoing at the same time. I am rebuilding a very rusty M416 next to the generator. But I have determined that I do have very good fuel flow to the injector pump. there is a returning fuel to the onboard tank. I have read the manuals some but I would love copies of the "Ambac stuff". As this unit has not been running in some while, it maybe a stuck plunger. Is there a way to tell or a way to free it. I think I do not want to take the IP off the unit if I do not have to.
Thanks to all.

 

[jamawieb]

Thank you all for the information. Like all of us i have several projects ongoing at the same time. I am rebuilding a very rusty M416 next to the generator. But I have determined that I do have very good fuel flow to the injector pump. there is a returning fuel to the onboard tank. I have read the manuals some but I would love copies of the "Ambac stuff". As this unit has not been running in some while, it maybe a stuck plunger. Is there a way to tell or a way to free it. I think I do not want to take the IP off the unit if I do not have to.
Thanks to all.

If you do a search for mep-002a plunger you will find a bunch of threads on the issue.
1st can you move the throttle arm that is located on the right of the injector pump up and down easily? It should move freely with little to no resistance. If it's difficult to move, then the plunger is going to be stuck as well.
I've had great success with using lacquer thinner. I will fill the last fuel filter container, half full with lacquer thinner, then start to prime the unit with the fuel pumps. As the unit is priming, I use a socket on the blower and rotate the motor over several revolutions and as I'm doing this I move the throttle up and down. The lacquer thinner eats the gunk in the pump and the diesel that is in the tank will dilute it. But the key is to make sure you rotate the motor and move the throttle arm as soon as you start priming because the lacquer thinner will be pushed back into the main tank.
I have done this to about a dozen generators with stuck plungers and it has worked. So far it has not caused any problems because lacquer thinner will swell the o rings in the pump.

 

[Guyfang]

Outstanding idea! We always used STP fuel injector cleaner, but normally only when it was running. but this sounds like a better idea, when you can not get it running. .

 

[Ray70]

Definitely sounds like a good idea to remove the varnish, however, if Redlight's plunger was frozen and he tried cranking it over already then his driver washer is most likely now snapped in half. The drive washer's purpose is to act like the weak link and break to prevent further damage to the pump. So I'm assuming your method would be great as long as you start working the lacquer thinner into the pump before even attempting to crank it over.
Redlight, I'll PM you the stuff I have from Ambac. I don't think I can insert the pdf's here.

 

[jamawieb]

Not necessarily, if the plunger stuck at the highest point then he would be okay. From my experience, the plunger will still move inside the head and will not break the drive washer, it will just get stuck at the highest point and stay. I believe what happens, is that over an extended period of cranking, the plunger will start to move back down but there is still enough gunk on the plunger to jam it, which in turn breaks the drive washer. You maybe right with Redlight's situation since it sounds like he's cranked it several times over to see if fuel is coming out the injector lines.

Redlight I would definitely take the pump off and clean it before buying a new one. They are extremely simple to work on and the parts are still available from Ambac.

 

[Ray70]

When the motor is turning the plunger rod is doing 2 things, the cam lobe is pushing the plunger rod in and out and the drive gear is rotating the plunger rod. The driver washer (aka dogbone) is what connects the drive gear to the plunger rod to rotate it, so if the plunger can not rotate freely the drive washer will immediately split in half regardless of where the plunger is on its in/out pumping stroke.
Then the throttle lever connects to the metering sleeve which slides up and down on the plunger rod. So a sticky throttle lever is a good indication that there's issues with varnish inside the pump.
I agree with you that his best bet is to remove it and check it out before buying a new one. Its much easier to deal with the original than to have to get buttons and time a new pump... not to mention to price! The hardest part about rebuilding them is removing and installing what people call the " Jesus" clips.... so-called because you'll be yelling "Oh, Jeezis" as you're trying to fiddle with them!