Running MEP-003 without generating power

[Crawdaddy]

Hopefully this evening I will get my generator up and running for the first time. I know you're not supposed to idle these sets, but having never run it before due to it missing parts from GL, I don't want to inadvertedly run it too slow while doing operational checks and burn up the voltage regulator or other parts.

Looking at the setup, there's the 2 main power connectors coming from the gen head to the output box and what I'm guessing is the small wire gauge exciter wiring going to the output box. Can I just disconnect these three connectors and be "safe" from cooking anything on the set? Or should I just fire it up and hope I can get it at the right speed really fast?

 

[gimpyrobb]

Speddmon posted that the throttle pulled out 3/4 of an inch(I think) is where his genset stays at. I would look for his thread/posts and see if the "3/4" is correct, then adjust from there. You will fry it more from underspeed than over speed.

 

[jbk]

throttle position will vary from set to set due to different gov. adjtments, but out halfway is at least a starting poiint. get you a meter to read frequency and voltage. kill a watt comes to mind sold at hf. you have about 30 or 40 seconds to get the rpms up before you risk the reg. probally a good idea to read over the operations tm to familarize ypurself.

 

[lonegunman]

Why can't you idle or run a MEP-003 withload a load? We used them for my entire career and I never saw one die from running.

 

[PeterD]

Why can't you idle or run a MEP-003 withload a load? We used them for my entire career and I never saw one die from running.

Don't confuse loaded state with idling... You can't idle the engine (run it at less than the specified RPMs) because that will damage the regulator. This happens because the regulator tries to force the generator head to put out rated voltage, but the speed is insufficient to do that, and so the regulator tries harder, and harder, and harder, eventually burning out the output transistors.

Running without a load (for short periods of time) is OK, though for some water cooled diesel generator sets, that will lead to eventual wet stacking.

 

[glcaines]

The TM for the MEP-003A doesn't mention that you shouldn't idle the genset, but I believe the MEP-002A manual does. However, idleing the MEP-003A will definitely damage the VR.

 

[Crawdaddy]

I have never gotten this generator to run because it was missing parts and has a bad starter. So, once I get the starter replaced, I'm going to crank it up just long enough to see it run with the connections to the output box disconnected, which should be less than 10 seconds. Then, I'll shut it down and reconnect the wiring, start it up again, and immediately adjust the throttle to be at 60hz according to the meter and hopefully an external multimeter if I can rustle one up that can read frequency. I do not plan to ever idle the set because I have read all over the TMs and threads that idling=cooked VR.

My bigger reasoning for disconnecting the output wiring is that when I've initally tried to crank the set up with the bad starter, the starter didn't have enough oomph to smoothly spin the motor around with the wiring connected, presumably because of the extra drag of the gen head trying to start producing. Once I disconnected the wiring, the starter would turn the engine smoothly, but still too slow. The existing starter would start smoking after literally 3 seconds of cranking. I have another one in hand and once I get it installed, I'll proceed as I outlined previously, unless that's a bad idea. I just want to give this engine as much chance to start and run initially as possible.

 

[glcaines]

I wouldn't bother disconnecting the wiring. I would go ahead and replace the starter and try to start the engine. A good starter should have no problems starting the engine. I know you said you read the TMs so you probably already know that you need to keep holding the starter switch in the start position up to 10 seconds or so after the engine starts until the oil pressure builds up.

 

[derf]

My bigger reasoning for disconnecting the output wiring is that when I've initally tried to crank the set up with the bad starter, the starter didn't have enough oomph to smoothly spin the motor around with the wiring connected, presumably because of the extra drag of the gen head trying to start producing. Once I disconnected the wiring, the starter would turn the engine smoothly, but still too slow. The existing starter would start smoking after literally 3 seconds of cranking. I have another one in hand and once I get it installed, I'll proceed as I outlined previously, unless that's a bad idea. I just want to give this engine as much chance to start and run initially as possible.

I don't think you should get any kind of drag on the gen head at starting speeds.
Maybe a shorted field coil or something was drawing too much current and making the starter turn slower?

I think every time you start a MEP genset if sends 24V to the field to "field flash" the set. I do not think the 24V sent to the field coil should cause any noticeable change in the starter function. The field coil should only draw a few amps (I think) and the starter might draw a couple hundred.

What seems like a bad starter might also be a bad battery or bad starter wiring. If the starter engages and turns the set over then it is probably OK. A bad starter or bad starter brushes would fail to turn the unit over, I think.

I'm speculating here in general terms but the above makes me think you might have some wiring issues or connection problems. Are you using good batteries and are all the connections good and clean?

 

[Crawdaddy]

I don't have any spare batteries, much less 6TLs, so I've been borrowing the batteries out of my deuce. With the gen head wiring connected, the starter could turn the motor 1/4 to 1/3 of a turn, get stuck for a second, move another 1/4 to 1/3 turn, get stuck. I disconnected the gen head wiring, and the starter spins the motor with no getting stuck, albeit slowly. I have another starter in hand that is missing a screw in it, so once I find a screw to fit the spot I'll put it on and see if the engine spins faster.

 

[derf]

If the batteries can start your Deuce, then they should be able to spin the 003 with no problems. Make sure your wiring and connections are good. A bad wire or connection can cause similar symptoms.
I'm still pretty sure the gen head should spin freely at startup. Even if the field is energized I don't think you should get enough magnetism in the head to affect the starter RPMs. I might be wrong on this.

Can you not take the screw from the starter that is on the unit and use it on the starter in hand?

 

[Crawdaddy]

That was the plan, except the screw on the old starter is STUCK. Even taking the impact with a phillips bit isn't budging those machine screws when they virtually fall out of the new one I have.

The wiring should be pretty good and clean. I virtually had to reassemble the wiring at the starter as it was mostly disconnected when I got the genset. However, in reassembling the wiring again, I will double-check to make sure everything's good and tight. I wanna see this thing run!

 

[derf]

In theory, you SHOULD be able to disconnect all the wires from the head and not do any harm. But, I cannot be 100% sure about not damaging the VR.
If it starts, though, it should be fine. Just don't let it run slow for any length of time.
Start it, give it a few seconds to get up to 1800 or so RPM and if it does, then you probably won't be damaging anything. Keep in mind it was DRMOd for some reason and may already have a bad VR or bad head or something. OTOH, it is often good to have obvious visible issues like your starter wiring. Then you can assume that the problems are related to the visible issues. What I mean is your unit probably just has starter issues if the wiring was disconnected. The only thing I could find wrong with my 016E was a stripped terminal on the new looking Yanmar motor starter.

 

[Crawdaddy]

This genset was missing an injector line, injector return line, had oil lines disconnected and broken, some messed up wiring, missing start relays. My theory is it has some illness and was cannibalized afterwards. Hopefully it isn't a pile of scrap!

 

[Crawdaddy]

I've been trying to get this MEP-003A generator running, and have met resistance every step of the way. First, I had to repair the wiring harness and replace a missing injector line, missing injector return line, hooked up the disconnected oil line, and replaced a broken oil fitting. So, everything seemed to be in one piece finally. So, I went to start it up. The starter didn't seem to have any oomph to spin the starter, so I got another one and this one seems to be spinning the engine fine. Now, it seems like I'm not getting any fuel to the injectors.

When I turn the master switch to the run position, the pumps click and slow down their clicking. Then I can hear the fuel draining back into the tank from the fuel return line. All seems good. But, I have no fuel coming out of the injector pump. Pulling an injector line, then cranking produces no fuel at all, and the inside of the injector pump output port is bone dry and seems to have a little rust.
My grandfather suggested we pull the center cover to see if there was anything to see despite me telling him there's nothing in there. So, I pulled the cap, retainer, and spring. Leaving it open and cranking, nothing came out while cranking, but a second after stopping cranking, fuel started coming out of the hole with a good bit of force.
My grandfather seems to think it needs a rebuild because no fuel's getting to the injector ports, but I think it just needs to be retimed. Who's right? I guess it's more or less a moot point because if I pull it off to retime it, it would be just as easy to send it off to be rebuilt so I know it's in good operating condition.

Am I heading in the right direction with this? I think I am, but I'm not sure.

 

[derf]

Is the fuel shutoff solenoid working correctly?

I thought the return line was on the output side of the injector pump.

You might just have air in the system or your injector pump might need attention.

I haven't gotten that far with my 003, yet, but will soon.

 

[Crawdaddy]

The fuel shutoff solenoid does lift up when I hit the starter. I think I've bled the system. I opened the bleeder on top of the fuel filter until I got fuel out of it, and left the set in the run position for long enough that I think the air would have gotten pushed out, probably 5+ minutes by now.

 

[derf]

What I wrote above is incorrect about the fuel returning to tank. Read here:
MEP 002A and 003A - Steel Soldiers::Military Vehicles Supersite

Have you checked the check valve?

 

[jbk]

sounds like you removed the delivery valve spring and holder and plastic spacer. you should be able to see the plunger move as you spin the engine. if not it could be broke or froze up. refer to tm for pump removal. you will have to set the engine up, no. 1 up valves closed anyway the procedure is in the tm. you should be able to find somone local to rebuild you pump, fairly common.