MEP105A Gen Starts and dies

[ICAT]

I work for a small municipality and we have a generator that just starts and dies. Fuel filters have been changed. Speed switch and oil pressure switch have been checked according to the -12 manual. Any help would be great.

 

[155mm]

First thing i can think, holding start switch in start position until oil pressure comes up

 

[uniquify]

Do any warning lights come on?

 

[Guyfang]

What is a MEP105A?

 

[ICAT]

it shuts off like it was turned off

 

[ICAT]

MEP105A is a 60k generator

 

[Guyfang]

OK, now I got you. The precise power model. Now we are on the same page.

Need some backround info.

Have you ever seen it work right? Did someone work on it before it started doing this? Is that all that was done, fuel filters changed?

Also, does it shut off as soon as you let the S2 start switch go? Or will it run a bit longer before shutting down?

 

[ICAT]

Found it. It was the check valve on top of the injector pump. Took off the t-fitting on top of the injector pump and it started right up. Shot fuel everywhere but it started and ran. So I took it back to my shop and empty a can of brake cleaner on it and the ball started to move. There was a lot of rust and crappolla in it. Thanks for the replies

 

[Guyfang]

That's a pretty normal fault for this set. Dump a few cans of carburetor or injector cleaner in the fuel supply. The L1, (Engine fuel shut off solenoid) and the FL-1 and FL-2, (fuel level switch)and the L2, (Day Tank solenoid) tend to also get gummed up with the lacquer.

I am surprised that you have a MEP-105A! Its the rarest of birds in the Army power generation world. They bought thousands of MEP-006A's and many hundreds of the MEP-115A, (400 hertz) but very few MEP-105A. There simply wasn't enough need for a precise power gen set at the time, other then the 400 hertz generators. I spent almost 30 years working on army gen sets, and saw very few, maybe 10-12 sets. I assume yours has the electronic governor and actuator set up. The OLD, OLD, OLD Hyd governor and actuator were a nightmare to work on. If you look in the -24P you can still find this gear, but we changed over in 1980 I think. I worked more then 8 years on the 115A model. Its the same as the 105A, just a different main gen and a few other parts. GOOD gen set!

 

[ICAT]

it was purchased from a federal surplus as a emergency generator. We have had it installed for a year. This is the first problem we have had so we are pleased with it

 

[Guyfang]

This gen set likes a full load. If you run it under 50-60%, it will begin to wet stack real fast. The crankcase blow by will begin to slobber like a professional drunk. If you can, keep it at least at 75-80%, even if you have to use a load bank. As a matter of fact, you will see in the TM's that the set had an optional load bank that was mounted on top of the set. We always set it for about 15 KW, then ran our normal loads. If the gen set went into the close to overload state, the load bank automatically kicked out. If the fuel tank is a steel tank, take a look see in it for water and rust. That's the reason the Army went to plastic tanks. If I remember right, the tank drain is the rear of the set. Take a gallon glass jar and drain out a gallon. Then you will see if its got water in it. The same with the day tank. Every 6 months or so, take a look see if your fuel supply is not real clean. Don't forget the fuel strainers in the 2 electric fuel pumps. I would run the set 2-3 times a year at as close to full load as I could for at least 3-4 hours. It will love you for it!

 

[ICAT]

I had to remove the injector pump to a shop for a rebuild.

 

[Guyfang]

Why? what were the symptoms?

 

[ICAT]

starts run and dies

 

[Chainbreaker]

Since you earlier said this about the check valve "There was a lot of rust and crappolla in it." I would blow out all the fuel lines while the injection pump is out for the rebuild if you haven't done so already.

Not knowing how often it was brought into service at your municipality and how many hours was put on it since purchased I'm guessing the fuel is OK...no water in fuel, no gumming of fuel and fuel tank is reasonably clean?

 

[Guyfang]

starts run and dies

When this set starts, runs and dies, its always good to check the L1 solenoid. Did you do that? And the 24 VDC that opens it?

 

[ICAT]

Ok, so here is the deal. The injector pump needed to be rebuilt. got it done. After reassembly a slight distortion in one of the injector line washer caused a leak. Also there is a dead crank switch which allows you to crank the engine without it starting. Well don't trust the label. the switch was upside down. i started to troubleshoot an electrical problem that didn't exist. So it's up and running.

 

[Guyfang]

You are just one of legion, when it comes to such "problems". Never trust anything when you get a machine from someone else, and you have never seen it run right. Always look and test. Glad you got it up and running. Resist the urge to adjust the electric governor, unless you follow the TM to the letter. But, all in all, that's a good gen set when its taken care of.

The IP washers, well, it happens. Mostly it was that they were installed backwards. Sometimes we just loosened the flow through bolt, spun the washer, and tightened it down. Sometimes it worked, sometimes it didn't.

Good job!

 

[ICAT]

Gen is running great. It just started leaking out of the final fuel filter. Looks like i need to get a filter kit with new gaskets.