Mep-002a Start but runs rough when load applied.

[Pechan]

Hello,

I have been lurking here for several years but first time poster.

I have a Mep-002a that serves as a backup for our solar system ( off grid house ).

We have had the unit for 3 years and run it approximately once a week in the winter for 6 hours or so. Casper, WY weather so today it is 0 degrees out.

This fall I began to have a few problems with the generator dropping rpms under load then recovering within a couple of secconds.

I suspected the fuel pumps and replaced them with a rotary vane pump THIS ONE. This didn't really fix my problem so I replaced the injectors.

This seemed to solve the issue for a week or so. But I tried to start the unit yesterday and now it completely drops out under load and does not recover.

I filmed a video of the problem which can be seen here: YouTube Video

What should I check next?

Thanks!

 

[Triple Jim]

Sticking valve? I'll let the guys more experienced with diesel engines comment, but the "close to run" cover that makes the cooling air pass over the engine's cooling fins is missing. If you ran it very long under load that way, I would expect you may have overheated engine parts.

 

[Pechan]

Thanks for the reply Jim.

I do have that cover and I recently removed it to replace the injectors.

With our 0 degree temperatures for the last couple of weeks I can't see it causing a problem. Maybe I'm wrong?

Matt

 

[jamawieb]

It looks and sounds like its starving for fuel. The governor has it at full throttle and it's still stalling. I would make sure your filters and tank are clean first. You could have trash in the tank that is getting sucked onto the dip tube, clogging the flow of fuel. Then move to the check valve that is right after the filters, make sure it is clear and finally move to the return line from the pump to the tank.
What happens if it runs for a long period of time with no load???

 

[dependable]

In your video, it looks like there is a fuel leak on one of the injection lines.

 

[snowtrac nome]

look at the return line and ck there for obstructons if you have a return issues the pistons in the pump and injectors will fail to fill properly causing starvation issues

 

[Triple Jim]

Matt, no I don't expect you had an overheating problem if you didn't run it for an extended time under load without the cover.

 

[jamawieb]

How old is the fuel? I had a customer who bought a genset from me and left fuel in the tank for 2yrs. It started fine and he hooked it to his house and it died under load. Finally figured out that algae started growing in the tank. After he cleaned the tank, changed the filters, and put fresh fuel, it was back to running right.

 

[Guyfang]

Pechan,

This sounds like classic fuel starvation. Everyone above me thinks so also. I would start with the fuel tank and go to the injector pump. Clean, blowout, soak in carb cleaner, everything in the system. If you think you are up to it, take the injector pump apart, and soak it in carb cleaner. If not, toss in a can of carb cleaner to the fuel tank, and let it run an hour, or two. Shut it down and give it a day, or two. That way the cleaner gets some time to work. Put the whole thing back together, with teflon tape on every screw on connector. Make sure everything is tight, but don't "Man Mountain Dean" tighten the connections. And for good measure, toss in a can of carb cleaner with the first batch of fuel. That will clean out the electric fuel pumps. And yeah, don't run it too much without the covers. The airflow is channeled through the set for best cooling. Without the cowling and covers, it simply doesn't cool right. Takes longer to warm up, and gets too hot at the end. Change both filters, and clean out the fuel/water separator. You can unscrew it, and soak it in carb cleaner. Don't forget the check valve.

 

[Firebrand]

Agree ^^

Also, check your air filter and make sure there are no obstructions or blockages. Diesels need the same amount of air regardless of fuel or load.