MEP-006A Issues

Guyfang said:

Was a while back. Also an excitation card and the regulator. But its been a few weeks. Plug in the Part #'s and NSN's.

Click to expand...

sorry i guess my question is what is the BIG AUCTION SITE? do you have a link?
thank you.

Ebay

Just what do you need? the whole thing? or the cards?

There are two in the big auction site. 6115-00-244-1214

Guyfang said:

6115-00-244-1214

Click to expand...

ok will take a look thank you and I'm just going to replace the whole thing.

I'm back working on the camp's generator. After I got it working for them a few years back (looks like 2019 from the earlier posts in the thread) they neglected my pleads to operate and load bank it once in a while by one means or another. It never got used until last year when the camp ownership changed and the new leaders wanted to check it out. I wasn't there but they ran it for a while with an unknown amount of load until it shut down for unknown reasons. Yes, I know almost nothing about what they did.

Not knowing where else to start beyond the fact that the fuel in it was probably a decade or more old and the fuel filters had never been changed, I asked them to drain the fuel and refill it and change the fuel filters. They did that and could not get it to start again, so that's when I got pulled back into it. I found that the overspeed light was on and reset the speed switch. Now the only fault light that is on prior to cranking is the low oil pressure light, which I think is normal according to the operator manual. That got it to where it would turn on the fuel pump and fill the day tank but it still wouldn't start normally. It would start on starting fluid though. After trying to check several things I did manage to get it started without starter fluid a couple times (not sure what changed to make it start), and it even ran for a couple minutes once. But it would not hold speed well and typically would start and then gradually slow down and die. It just seemed to me like it was running out of fuel, but the day tank was always full of fuel. That is when I ran out of time that day. That was about a month ago.

That brings me to today. It had some fuel leaking from the stage 2 fuel filter so I replaced that filter again and cleaned everything well and it stopped the leaking. I thought it might have been pulling air in at the leaks, but that didn't make any difference. I tried to run through all the troubleshooting items in TM 5-6115-545-12 table 3-3 "engine cranks but will not start". I know it's got new clean fuel, the day tank is full, and I checked the fuel flow through the stage 2 filter and it is not plugged - it flows a good solid stream. The engine did run a month ago so I have no reason to believe that the injectors (nozzles) are bad. It just acts to me like it has a fuel delivery problem. That led me to the troubleshooting in TM 5-6115-545-34 where it mentioned to check the solenoid in the injection pump. I verified it has continuity between the terminals, ground at the outboard terminal, and ~24V at the inboard terminal with the switch on run and battle short engaged. Just to be sure, I hooked up a 24V jumper to the inboard terminal and you can audibly hear the solenoid "clunk" to engage and disengage. It still wouldn't run with the jumper left on, either. So I loosened the 4 injector lines at the pump that I could reach easily, and no fuel came out of any of them when cranking. Section 14-43 of the -34 TM seems to indicate that if you go through the steps I have done and don't get any fuel out of the injection pump, then something in the injection pump has failed.

So... is there anything else that I'm missing before diving into the injection pump on this unit? I think I've done my due diligence on ruling out everything else, but I thought I would ask the experts here before I take that leap. Thanks in advance for any advice you can give!

Good morning. My first thought is battery condition, state of charge etc. Slow cranking speed can make the difference between starting and not starting. If you have access to a battery charger it would be good to charge those batteries over night and also load test them if possible. It's always a good idea to begin with known good batteries when trouble shooting a no start. If you're unsure about the age/condition/state of charge on those batteries, get some new ones.

Second, I'm actually not familiar with the 006. Does it have a manual lift pump on the side of the engine? The 806 version does. It also has a lever on the side of the manual lift pump where you can hand prime the fuel system without cranking the engine over and over thus running the batteries down. Look to see if there's a hand lever on the lift pump. Open the delivery line at the IP and hand prime until you get fuel coming out. If this 006 has an electric lift pump, just turn on the S1 and open the delivery line at the IP. When fuel starts coming out, close the delivery line and crank it over with your newly charged or replaced batteries. If it still won't fire the next thing to check would be the MPU. It's what sends the RPM signal to regulate the fuel supply from the IP to the injectors.

loosegravel said:

Good morning. My first thought is battery condition, state of charge etc. Slow cranking speed can make the difference between starting and not starting. If you have access to a battery charger it would be good to charge those batteries over night and also load test them if possible. It's always a good idea to begin with known good batteries when trouble shooting a no start. If you're unsure about the age/condition/state of charge on those batteries, get some new ones.

Second, I'm actually not familiar with the 006. Does it have a manual lift pump on the side of the engine? The 806 version does. It also has a lever on the side of the manual lift pump where you can hand prime the fuel system without cranking the engine over and over thus running the batteries down. Look to see if there's a hand lever on the lift pump. Open the delivery line at the IP and hand prime until you get fuel coming out. If this 006 has an electric lift pump, just turn on the S1 and open the delivery line at the IP. When fuel starts coming out, close the delivery line and crank it over with your newly charged or replaced batteries. If it still won't fire the next thing to check would be the MPU. It's what sends the RPM signal to regulate the fuel supply from the IP to the injectors.

Click to expand...

Good morning and thanks for the post! The batteries on this set are less than a year old and were charged completely over the past couple days. It is cranking faster now than I have started and ran it with before, and is still showing ~25.2 volts after multiple cranking events. So I do not believe batteries or cranking speed are the problem.

This set sounds different from the 806, but I have no experience with those. There is a solenoid style lift pump to fill the day tank, and I have verified full fuel flow to the inlet of the injection pump as stated above. However there is still a charge pump inside the roosamaster stanadyne injection pump that I don't know how to check separate from the main injection pump.

As far as I can tell, there is no mag pick up on this set. It picks up speed from the speed switch on the opposite side of the engine from the injection pump, and I am getting power through the appropriate circuits of it that send power to the solenoid on the injection pump. And the way I think about it (which could be wrong) when I applied the 24v to the injection pump solenoid, that should essentially bypass all safety systems on the set and make it run if it has fuel, right? I set the throttle at what gave it 60 Hz last time I was there and marked it to ensure it wasn't tinkered with, which I think are the only inputs to that pump besides the gear train and fuel.

One thing I should have mentioned last night, I checked the fuel drain out the top of the injection pump yesterday and it was bone dry. I tried to manually fill that line with a funnel from where it dumps back into the top of the day tank, but it made no difference. Makes me think that the solenoid may be clicking but whatever mechanism it moves in the pump itself may be stuck shut or at least sticky and not free.

Oh and since I did not specifically say it before, all fault lights work with the test switch and the only one on during my testing is the low oil pressure, which is overridden by holding the start switch to 'start'.

It sounds like you’re on the right track. I agree with you that applying 24vdc on that IP solenoid should get it to fire, regardless of faults/shutdowns etc. But because you have no fuel up to the IP, that’s what I would trouble shoot first before jumping that solenoid. Again, I’m not familiar with the 006, so I will bow out and let someone like @Guyfang who has much more experience with them. Good luck!

Good morning and thanks for the post! The batteries on this set are less than a year old and were charged completely over the past couple days. It is cranking faster now than I have started and ran it with before, and is still showing ~25.2 volts after multiple cranking events. So I do not believe batteries or cranking speed are the problem.

This set sounds different from the 806, but I have no experience with those. There is a solenoid style lift pump to fill the day tank, and I have verified full fuel flow to the inlet of the injection pump as stated above. However there is still a charge pump inside the roosamaster stanadyne injection pump (Never seen one go bad) that I don't know how to check separate from the main injection pump.

As far as I can tell, there is no mag pick up on this set. (correct. If it was a MEP-015A, it would have a mag pickup.) It picks up speed from the speed switch on the opposite side of the engine from the injection pump, and I am getting power through the appropriate circuits of it that send power to the solenoid on the injection pump. And the way I think about it (which could be wrong) when I applied the 24v to the injection pump solenoid, that should essentially bypass all safety systems on the set and make it run if it has fuel, right? (Correct) I set the throttle at what gave it 60 Hz last time I was there and marked it to ensure it wasn't tinkered with, which I think are the only inputs to that pump besides the gear train and fuel.

One thing I should have mentioned last night, I checked the fuel drain out the top of the injection pump yesterday and it was bone dry. I tried to manually fill that line with a funnel from where it dumps back into the top of the day tank, but it made no difference. Makes me think that the solenoid may be clicking but whatever mechanism it moves in the pump itself may be stuck shut or at least sticky and not free.


1. Turn on the set to the run position. Dont start it, just put the S2 in the run position.
2. Put the S7 in the up position. You should hear the fuel pumps run. Put your hand on both of them to insure that they are indeed pumping.
3. Look at the IP. On top, is a "T", item 13 in this picture. Break the line at the top of item 13. Do you get fuel out?
4. If so, then open the drain on the IP. Get fuel out?
5. There is a check valve there. I think its in the "T", or a fitting below the "T". That needs to be checked also. Dont just break the glass ball in it. Remove the check valve and soak it in something to eat the lacquer, holding the check valve closed. If you are not getting fuel to the IP, it aint never gonna start.

Oh and since I did not specifically say it before, all fault lights work with the test switch and the only one on during my testing is the low oil pressure, which is overridden by holding the start switch to 'start'.

Guyfang said:

Good morning and thanks for the post! The batteries on this set are less than a year old and were charged completely over the past couple days. It is cranking faster now than I have started and ran it with before, and is still showing ~25.2 volts after multiple cranking events. So I do not believe batteries or cranking speed are the problem.

This set sounds different from the 806, but I have no experience with those. There is a solenoid style lift pump to fill the day tank, and I have verified full fuel flow to the inlet of the injection pump as stated above. However there is still a charge pump inside the roosamaster stanadyne injection pump (Never seen one go bad) that I don't know how to check separate from the main injection pump.

As far as I can tell, there is no mag pick up on this set. (correct. If it was a MEP-015A, it would have a mag pickup.) It picks up speed from the speed switch on the opposite side of the engine from the injection pump, and I am getting power through the appropriate circuits of it that send power to the solenoid on the injection pump. And the way I think about it (which could be wrong) when I applied the 24v to the injection pump solenoid, that should essentially bypass all safety systems on the set and make it run if it has fuel, right? (Correct) I set the throttle at what gave it 60 Hz last time I was there and marked it to ensure it wasn't tinkered with, which I think are the only inputs to that pump besides the gear train and fuel.

One thing I should have mentioned last night, I checked the fuel drain out the top of the injection pump yesterday and it was bone dry. I tried to manually fill that line with a funnel from where it dumps back into the top of the day tank, but it made no difference. Makes me think that the solenoid may be clicking but whatever mechanism it moves in the pump itself may be stuck shut or at least sticky and not free.
View attachment 898721

1. Turn on the set to the run position. Dont start it, just put the S2 in the run position.
2. Put the S7 in the up position. You should hear the fuel pumps run. Put your hand on both of them to insure that they are indeed pumping.
3. Look at the IP. On top, is a "T", item 13 in this picture. Break the line at the top of item 13. Do you get fuel out?
4. If so, then open the drain on the IP. Get fuel out?
5. There is a check valve there. I think its in the "T", or a fitting below the "T". That needs to be checked also. Dont just break the glass ball in it. Remove the check valve and soak it in something to eat the lacquer, holding the check valve closed. If you are not getting fuel to the IP, it aint never gonna start.

Oh and since I did not specifically say it before, all fault lights work with the test switch and the only one on during my testing is the low oil pressure, which is overridden by holding the start switch to 'start'.

Click to expand...

Thanks @Guyfang!

I did your steps 1 and 2 yesterday and had good fuel flow to the injection pump inlet. I did not try to run the lift pumps with the top of the tee open, but it was bone dry there. I did not try to open the drain on the injection pump either. Is that also the timing cover? I am guessing that check valve is clogged so hopefully I am not headed for injection pump removal.

I hope to get back out there before too long and try again. Thanks for your guidance!

You can use the timing cover as a drain. just loosen the two screws, and then turn on the pumps. Give it a few min. If nothing comes out, loosen the lines to the "T" and take it out. If I remember right, the check valve should be in there or a fitting right below it. Its been 25 years since I had to clean one. If the check valve is good, (You should be able to plow through it when its clean) then you need to see if the solenoid is opening. Just because it clicks, is not a 100% that its opening.

If you do not run the electric fuel pumps when testing, then you are not going to "really" know if the fuel path is clear. It also might push and gunk/trash out of the lines. This is what I used baby food bottles for. Take a sample. Its supposed to be clean!!

I went back to the camp today to work on the 006A. First thing I did was to open the timing cover to check for fuel. It was dry, no fuel came out. So I pulled the check valve out of the top of the pump and sure enough it was completely clogged. I spent about 20 minutes with various pointy objects and a can of carb cleaner and an air hose and got it where it flowed easily (I did NOT punch out the glass ball). I pulled the solenoid off the top of the pump and verified that the linkage underneath would move. It did, although I'm not sure whether the amount of force was reasonable, but it seemed appropriate to me. After that I reinstalled everything but the timing cover and turned on the fuel pumps with battle short and they built up pressure against something and essentially dead headed like before, but no fuel came out of the timing cover.

So for the next step I disconnected the fuel inlet to the injection pump and verified that with battle short on, there was fuel flow there. There was a healthy flow of fuel out there. I had done this on Friday but thought I should confirm to be sure.

The next thing I did was try to get the inlet elbow fitting out of the injection pump since it might have some kind of inlet screen in it that could be plugged. That's where I got stuck. One of the injector lines wraps around the jam nut against the pump body, and of course it is the one on the inboard top side of the pump where none of my 9/16" tools would fit it. Some sockets were too short, some were too long, and none of my wrenches would fit. So that's where I had to admit defeat and start reassembling. Just for giggles, once I was done, I cranked it a couple times to see if cleaning out the check valve had done anything despite it still not filling the injection pump with fuel. I cranked it a couple times <5 seconds each and it did actually start. I adjusted it to 60 Hz and let it run but like before it wouldn't hold speed well and then after about a minute it started slowing down and I shut it off before it died on its own. With me reusing the injection line seals, and likely having bits of paint get in the sealing surfaces, it had quite the mess of fuel leaks around the hydraulic head.

At that point I loosened the timing cover and the pump was indeed full of fuel. It seemed to be clean fuel based on what I was able to capture. So I put that back on and tried to start it again and it wouldn't fire this time. So I gave up and headed home.

With the fuel pumps running with battle short on, it should be gravity draining fuel through the pump at all times until it is full, right? Basically any time battle short is on, the injection pump should be draining fuel out if the timing cover is open?

Any suggestions on what to do next? Any guidance on what kind of wrench might actually let me get that last injection line loose so I can get the inlet fitting out? If I need to take the injection pump out to have it rebuilt, I'm going to need that last line loose. That line seems to be the key stone holding me back from being able to do anything else that might lead to a happy ending here. Is there actually even enough room to remove the pump without removing the oil cooler as well? It seems tight to me but the -34 doesn't mention anything about it in the removal instructions.

We had a wrench called a "Half Moon". Something like this. Its a PITA. but can be done.


Will write more when I get back home.

Ok, back home.

When the set runs and slowly dies out, its a fuel delivery problem.

I don't know how well you cleaned the fuel system. Was there lots of trash in the check valve? Or was it just a matter of lacquer? Because the secondary filter and water strainer have been known to let trash go into the IP, when no one takes care of the set. That's why I would catch the fuel in a jar. Take off the fuel input line at the L1 (IP Fuel cut off solenoid). Drain off a QT, to get a good feel for the cleanlyness of the fuel. The water strainer could be covered in trash, or crap from old age, lacquer. That slows down the flow of fuel.

Did you pull the electric fuel pump filters and clean them?

I would then pull the L1 out. Hook up the wires to it, and test it to see if it opens the valve. I just love the taste of diesel. So I blow in the "T" fitting, with power off, then have someone turn on the power to the solenoid. You just need to push in CB1 and put the S2 in the run position. It should not let air through in the off position, and should in the on position. Easy. Then, set the L1 back in the IP, correctly. If you don't get it right, set wont start. Then screw in the bolts until they almost make contact with the cover. Hook up the fuel lines to the IP. Not the injector lines, just the fuel input line. Try and start the set. Crank it over. Put something under the IP to catch the fuel. There should come a whole bunch. Let it pour out a bit. Here again, glass bottle, or a clean plastic container. See what the fuel looks like.

Item 47 is a filter. Check it.

I have worked on this set again a couple times in the last month. I followed all the above advice and came to the conclusion that the injection pump had issues inside and needed to come out. So I did, took it to a reputable local shop and had it rebuilt. He said it had lots of crud in it and the governor was stuck. Today I reinstalled it and the set did run, but it still has issues. My suspicion is that the governor isn't right for a generator application. Once it was set at 60 Hz, warmed up a little, and had load applied, it would not maintain frequency. At 20 percent load on the gauge (which I think is reasonable based on the items being powered) there wasn't any more throttle adjustment left to get it above 57 Hz. When I opened the circuit breaker to remove load, it went way high on frequency. That seems like a dead giveaway to me that the governor isn't doing its job.

Any other thoughts before I call the shop on Monday and see when they want me to remove it and bring it back in? As mentioned above, it's fresh out of the shop after a rebuild and I verified fuel flow into it again today (felt like a good idea to put some fuel through all the filters before I hooked it back up anyway).

Video proof that it was running today at least.

Always seems to be one step forward and two steps back with this thing!

Had you told us that you were going to get the IP rebuilt, I would have told you to copy the rebuild info, from the -34 Tech Manual. The spec's are different for the military and civilian IP.

Guyfang said:

Had you told us that you were going to get the IP rebuilt, I would have told you to copy the rebuild info, from the -34 Tech Manual. The spec's are different for the military and civilian IP.

Click to expand...

When I took it to the shop, I told him that it was a military MEP-006A generator, which he wrote on the ticket. He's done military stuff before so I would have thought he had what he needed to get the right specs. When I got it back he even had put a new coat of CARC on it, which I wasn't expecting. I was expecting it to be right for the application when I got it back, which has been the case for everything else I've ever taken him.

Anyway, we're past that point, the IP has been out, has been rebuilt, and I've reinstalled it. I've been using the -34 to guide my troubleshooting and for instructions on how to remove and reinstall the IP, so I'm familiar with those sections. I'm confident that it was at the point that IP removal was necessary - the troubleshooting instructions led me to that point and it passed all the external checks you had given me, too. I'm not as familiar with the parts regarding rebuilding the IP because that's what I expected the shop to do. Can you please point me to the specs that are different that might have been set wrong? Are you referring to the delivery values in table 14-2? Or the procedure for setting the high idle speed with the screw and nut on the linkage and the knob to set the droop? Or something different than that? Is it reasonable to think that I can set the high idle speed limit lower than it is now and then turn the speed droop knob clockwise to increase droop? Or does it just need to go back to him with a copy of chapter 14 section VIII?

FYI I got and tried the "moon" wrench that you recommended for the top inside injector fuel line but it didn't fit either. The only way I've been able to get to it was to remove the inlet cap for the vane pump and put a 'torque adapter' on it with a long 3/8" extension to get the ratchet outboard of the IP. It's a bit clumsy but that was the only thing I found that was long enough to get past the end of the pump body and short enough to fit between the IP and the cylinder block and also not hit the oil cooler. Just in case anyone else reading this later has trouble finding the right tool to get that fitting loose.

I normally tell folks to copy the whole section on IP rebuild and testing. Give that to the shop.

I got another chance to work on the generator yesterday. At the IP rebuilder's advice, I tried adjusting the droop screw, but it still wasn't acting like it should. It would bring the engine speed back up, but when I opened the circuit breaker, it would jump up above 62 Hz. He had given me contact information for a local generator repair / testing company, so I called that guy. He was super nice and suggested that I lock down the outer set of levers on the IP which free floated originally, in whichever direction didn't cause the engine to slow down / shut down. I am guessing that is one of those differences between military and civilian setup, but that was just the attitude adjustment it needed.

After that, it varied less than 0.5 Hz between 0 and 45% load (all the load their facility could create by turning EVERYTHING on), and it stayed at the original set point when I opened the breaker. It may be a hybrid setup between military and civilian specs, but if it works, neither the camp director nor I care. He contacted the generator service company to come out and load bank it to full power to confirm it behaves, and fine tune the droop if needed. That should happen in the next few weeks. So at this point, I am hands off for this project. The camp director knows how to start and operate the set and knows it is imperative to operate it with as much load as possible, for at least an hour every month or two to make sure it will work when it is really needed. And he's already talking about having the electrician trench over for another manual transfer switch to their other building (on a separate electric service now) so he can provide backup power for it too and maybe get enough load on it to be confident it won't want to wet stack. I am just happy to have it functioning again before winter.

Video or it didn't happen...