MEP 003 Starting and low rpm problems

[Nitrodiver]

ggBrief back story. I picked up two MEP-003A generators recently. Both have all the Important parts. One has the injection pump off of the set and one injector out of the head. This one is said by the seller to have a “fuel problem” is why It was torn down whatever that actually means. The other one (the one I am working on) is said to have an “electrical problem” but the unit is complete and intact.


The fuel that was in the tank/system smelled of varnish and appeared to be old red diesel that was in it since it left the military. I removed the fuel tank cleaned it out. Cleaned all the lines, fuel pumps and pump filters, filter housings and lines. All things being considered none of the filters looked all that bad and I couldn’t find any debris in the prefilter. Put in new filters and bleed the air out of the system to the injection pump with new fuel. Cracked all 4 injection lines at the injectors to verify I am getting fuel at the injectors and too bleed any air out of the lines. Also checking to see if I was getting fuel returning to the tank from the return line. All looked good.


Went thru the preheat 1 min cycle. Primed the fuel system before the preheat and again quickly after preheat just to insure there’s plenty of fuel pressure. Then tried to start it for no longer than the recommended 15sec. After running the batteries down on the Deuce and after 3or 4 cycles of this, it would not start. After consulting the search bar here. I found that some say to pull the throttle out to full throttle and read that some were using crank times of up to one minute on known good running sets. Sounds as though they are really cold natured. I went thru the same process but with the throttle out all the way and a longer crank time making sure the starter doesn’t get too hot. Eventually I was able to get the set to fire off and run, which was a partial relief. Bellowing lots of smoke and running at low rpm. Thinking this was from the old/bad fuel that was left in the injector pump and injectors it would soon clear up and come to full rpm, which it did not. As soon as I let off the momentary start switch for it to go back to prime and run it died. I did this a couple of times in an attempt to get good fuel to the cylinders. I know that it’s not good to let these sets run at low rpm or idle so I released the start switch and it died. After the final attempt I still had the same results.


It was almost dark outside and I couldn’t see the fuel shut off solenoid. It could be that when I let the start switch return to prime and run that the solenoid shut off the fuel and killed the engine, is one thought that comes to mind, the “electrical issue”. Which I an going to verify during daylight. Doesn’t look as though the injection pump has been tampered with so the timing should be correct unless it has jumped time somehow, if that’s even possible on these gear drive pumps.


Obviously I don’t want to cause more problems by running it at low rpms for too long. I would think that after a couple of min of run time, all attempts combined. That if it was going to clear up it would have by now if it was just bad fuel. I’m afraid that trial and error method of figuring out what the issue/s are will cause more harm than good. So I thought I pose the situation to the gurus here for some help on what could be causing the above symptoms?


My gut says the injection pump is gummed up after having old fuel sit in it for who knows how long. Since it is the heart of any injected engine that’s a good place to start. But after reading the rebuild manual on these injection pumps. It seems quite in-depth and requires special tools which usually equates to as much cost as a new pump. Then again I could be way off on my entire diagnosis. Any help would be much appreciated in getting this set running. Thanks in advance.

 

[Light in the Dark]

Have you tested the glow plugs to ensure they are working? Have you verified the wiring to the oil pressure safety switch is intact and connected? It will shut the set down, if it does not sense proper pressure.

 

[Nitrodiver]

I disconnected the oil pressure switch beforehand so it wouldn’t keep it from starting. I forgot to meantion that. But it meters good per the TM. I haven’t been able to get it running long enough to hook it back up and see if it shuts down the motor should it be bad and my meter is lying. I am also getting 40psi oil pressure, what little time it ran.

I did meter the glow plugs but I had my procedure backwards in my head so I need to redo that. I am getting 24V, or there about, to each of the glow plug terminals I verified that. I can certainly attribute bad glow plugs to the hard starting if that’s the case. Everything appears to be intact wiring, connectors tight, no frayed broken cut or damaged wiring at all that I can see anywhere on it.

Edited to add for those that come after me with this issue. if the oil pressure switch is N/O when it’s not running (TM testing procedure) once it sees pressure and closes. In order for it to continue to run after the start switch is released. Having the oil pressure switch disconnected the control system would not see the N/C signal its looking for and shut down. So yes you are correct in the operation of the oil pressure sending unit. Can’t believe I overlooked that but I will correct that. Thank you for brining that to my attention!

 

[Guyfang]

Hook up the LOP switch. If the oil PSI is good, the there is no reason to unhook it. Try and start and run the set. Pull the Throttle 3/4 out and start the set. Adjust the freq, if it runs, to 60, then leave the thing there. Resist the temptation to push in the cable when stopping the set. Tell us what happens during this experience.

Let's see if it will run, before you start wanting to tear the IP apart.

 

[Light in the Dark]

You should consider picking up a Kill-A-Watt meter for your testing purposes (so you KNOW its 60hz, instead of relying on a 40 year old gauge), as well as a can of Seafoam. Get that whole can in the tank, and let it cycle for a bit... start to do its magic. I have had sets not be able to maintain RPM due to fuel system gunk that quickly took the hint and left.

 

[Nitrodiver]

Let this be a lesson kids.....only work on things when you have ample time to think through what you are doing. Trying to rush to do things before dark or in a certain time frame will make you overlook simple things and compound your problems!! Not to meantion the idiot factor.

Upon a meditation session in the head. It’s plausible that the reason it’s smoking excessively with the engine running and only running at low rpms. Is because of a detonation effect before the piston hits its compression stroke. Why is that you ask....wait for it. Well that’s because there is a loose nut behind the wheel.

When the LOP switch is disconnected you have to hold the start switch in the start position for it to continue to run (covered above). However when you hold the start switch in the start position, according to the TM, that position also continues to fire the manifold heater and the glow plugs. So the engine can’t run correctly if the glowplugs are igniting or superheating the fuel before the piston hits it’s compression stroke. Hence the dense smoke and low rpms, at least in theory. That theory will be tested this afternoon because I would be willing to place a small sum on the fact that without the glow plugs superheating the fuel it will run as intended. I will not however wager on my level of idiocy!

Guyfang you are saying the SOP is once you find the throttle setting that produces 60hz. That’s where it should stay till the end of time?

 

[Light in the Dark]

I am not Guyfang, but YES... keep it at the sweet spot. You should never have to cycle RPMS down, its made to work at 1800. You may certainly need to fine tune your hertz based on loading of the genset, but keep it at full speed.

 

[Nitrodiver]

Light in the dark Yes those two items are on my list. The Kill A Watt meter I see the big box stores have it listed on there wedsites, it that something that you have been able to find locally or online purchase only? My main goal is to see that I have one or possibly two viable units that are not going to be money pits. Or do I need to part them out to recover my investment. If the Hz happens to be off a bit I’m ok with that till I can get one in hand. I am more concerned that it’s runs and generates power. I’m not in a hurry to put it to use just yet.

Seafoam is is what I was going to use, sound like you have had good luck with it. Thanks.

 

[Nitrodiver]

I will certainly keep that in mind. Thank you.

 

[Light in the Dark]

I bought mine on Amazon... but they have them at Home Depot, Wal Mart, etc. You can probably find something local.

 

[Light in the Dark]

Just pull the throttle cable out and lock into position. Rotate until you find the proper hertz setting for your load (its only this rotational adjustment you should have to worry about from here on out). And yes, go grab some Seafoam... in fact, get as many as you can afford (cans were $6.99 at the local Advance Auto Parts till the end of the month or something... instead of the normal 11-$12).

 

[Nitrodiver]

Roger that, thanks.

 

[Light in the Dark]

You can also just hook the two leads together from the LOPS too, which will give the system a false positive (this way, you have taken this part out of the equation as it will be a GO condition no matter what). If it runs with the leads hooked together, great. If you hook the LOPS back up and it doesn't run... there ya go. This way too, you don't have to keep the start switch activated longer than necessary to build the oil pressure to sufficient PSI. This will remove the variable about extended heating of the glow plugs too.

 

[Chainbreaker]

... My main goal is to see that I have one or possibly two viable units that are not going to be money pits. Or do I need to part them out to recover my investment.
Seafoam is is what I was going to use, sound like you have had good luck with it. Thanks.

I doubt either one of the units will end up being money pits if you approach it right. As it stands you have 2 MEP-003a's and it appears that one will be a runner without needing additional parts. I would focus on the one that is running, as you seem to be doing, and get it dialed in and load tested. Then you can make a decision on the 2nd non runner. As I see it you could get that one operational with some additional troubleshooting & repair parts if necessary unless it has major internal damage. Do some diagnostic evaluation first. Put a wrench on the fan shroud end and make sure it turns freely and its not seized before proceeding any further. If its seized up, then more work involved and you have to make a decision if its worth it to proceed. If it turns over freely, I would then take a look at the oil that's in it. Is it normal black used oil or does it appear to be thin with diesel mixed in (blowby)? Open up the control box and look inside behind the panel are all the components in place and wired up? If it all looks good and checks out I would then obtain any missing or faulty parts to make it a runner.

Depending on your utiity power situation and chance of longterm outages (hurricanes for you I guess!) you might want to have the 2nd unit as a working spare, or if not working, as a parts donor unit for your #1 unit. There are a lot of expensive parts that are likely good on your #2 unit even if you can't get it running. Your control box, starter, fuel pumps, injectors, glow plugs, DC voltage regulator, generator head unit, cylinder head, etc. could all come into use down the road if you plan to keep your #1 unit for a long time. These air cooled units are quite reliable and easy to care for. However, any genset with hours + years on it can have a electrical component or mechanical failure. If it were me, I would keep the 2nd unit and try to get it running when you have time. Then you know all the parts are good and it becomes your backup unit (2 is 1, 1 is none...sometimes). If you ever need to get your money out of it you will be able to sell a running load tested unit for MUCH more than a non runner. However, for me a 2nd working backup unit is just too precious to sell. During an extended outage it may be worth its weight in gold...well almost! Just my 2 cents.

 

[Keith_J]

Injector pump timing is set by the camshaft "lash" which is done by button thickness. Yes, the plunger also turns but this is for distribution and it can be off by a tooth or more and the engine will still run.

 

[Chainbreaker]

The below thread for -002a injector pump (same as -003a pump) may be helpful for you to read (along with the -003a TM & inj. pump manual) especially for your #2 unit that has alleged fueling problems with injection pump taken off it.

https://www.steelsoldiers.com/showthread.php?102043-mep002a-injector-pump

 

[robertsears1]

My 003 is very cold natured also. I just went out and cranked it up with only 10” of preheat and it started right up ( only 74 degrees right now). This particular set also requires one to hold the switch in start for approximately 15” after the oil pressure is up or it will quit as soon as you start to release the switch. A picture of my throttle knob extension is shown. I do remember one time when it would not come up to speed as it should. I was incorrectly slowing the engine before shutdown but learned why you should not do that. Luckily, I did no damage. The other pictures show where that issue was. Unclip and rotate the shroud that says do not run while open. Trace the cable up toward the fan and you should see a spring that has one end next to the end of the throttle cable with the other end around a threaded pipe device. On mine, the star washer that threads up and down on threaded pipe had slipped while I had slowed the unit down and the spring was not in the correct position. The book covers setting that. Once set, leave that throttle alone. At most you may turn it a half turn after getting set. That other picture shows a peculiarity of my set. Someone turned the filters around so that they sit proud of the side. I found my Kill-A-Watt meter at Lowes on the shelf.
Robert

 

[Guyfang]

Let this be a lesson kids.....only work on things when you have ample time to think through what you are doing. Trying to rush to do things before dark or in a certain time frame will make you overlook simple things and compound your problems!! Not to meantion the idiot factor.

Upon a meditation session in the head. It’s plausible that the reason it’s smoking excessively with the engine running and only running at low rpms. Is because of a detonation effect before the piston hits its compression stroke. Why is that you ask....wait for it. Well that’s because there is a loose nut behind the wheel.

When the LOP switch is disconnected you have to hold the start switch in the start position for it to continue to run (covered above). However when you hold the start switch in the start position, according to the TM, that position also continues to fire the manifold heater and the glow plugs. So the engine can’t run correctly if the glowplugs are igniting or superheating the fuel before the piston hits it’s compression stroke. Hence the dense smoke and low rpms, at least in theory. That theory will be tested this afternoon because I would be willing to place a small sum on the fact that without the glow plugs superheating the fuel it will run as intended. I will not however wager on my level of idiocy!

Guyfang you are saying the SOP is once you find the throttle setting that produces 60hz. That’s where it should stay till the end of time?

LITD said it all. The little up or down of the freq adjustment you need to do is so minimal, no need to worry a bunch about it. Under load, or without load. It should always be close. Then tweek it a bit as needed.

Get it running. Clean up the little things before they bite you in the BUTT. Clean up the fuel system with the sea foam. Prove it runs normal. Or not. Then we can address the real problem.

Oh, and maybe read the -12 manual a little bit more. Lots of good stuff in there.

 

[Guyfang]

My 003 is very cold natured also. I just went out and cranked it up with only 10” of preheat and it started right up ( only 74 degrees right now). This particular set also requires one to hold the switch in start for approximately 15” after the oil pressure is up or it will quit as soon as you start to release the switch. A picture of my throttle knob extension is shown. I do remember one time when it would not come up to speed as it should. I was incorrectly slowing the engine before shutdown but learned why you should not do that. Luckily, I did no damage. The other pictures show where that issue was. Unclip and rotate the shroud that says do not run while open. Trace the cable up toward the fan and you should see a spring that has one end next to the end of the throttle cable with the other end around a threaded pipe device. On mine, the star washer that threads up and down on threaded pipe had slipped while I had slowed the unit down and the spring was not in the correct position. The book covers setting that. Once set, leave that throttle alone. At most you may turn it a half turn after getting set. That other picture shows a peculiarity of my set. Someone turned the filters around so that they sit proud of the side. I found mt Kill-A-Watt at Lowes on the shelf.
Robert

The highlighted sentence is important. Before adjusting anything, read the book. Read it twice. If you are real smart, you will look for more info in the OTHER book. Always start with the -12 manual. Get smart. Then go to the -34 manual. Get smarter. If you knob dick everything adjustable without really knowing what you are up to, you can knob dick a perfectly good gen set into a non-op piece of crap. Next time you want to jump an oil switch, do it at the TB5-8 and TB5-9. That takes both the S5, (LOP) and the S4, (high temp) switches out of the equation.

 

[Keith_J]

My latest injector pump issue started with late injection symptoms and ended with the drive key broken. The key showed signs of fretting wear prior to breaking.