MEP-501 fuel pump seized.

[rustystud]

I have several MEP-501 and MEP-531 generators. Four to be precise. They have all worked great for years now. So I was surprised to find one of my MEP-501 engines seized the other day. I usually go around and either start-up my engines or just spin them around once a month. This last year though due to all the construction going on around here I neglected my engines until last week. All turned over or started right up no problems except this one MEP-501. So for the last four days I have spent a few hours trying to d\find out what happened. At first I thought the rings had rusted to the bore, so I removed the injector and filled the head with some anti-rust spray. I let it set for two days then tried to spin the engine. No go. Not even a little. Now I'm concerned. So I remove the starter and try turning over the engine with a pry bar. It moves a little one way then stops then goes back the other way then stops. Could be a rust spot on the bore but I decide to remove the fuel pump and inspect the cam. Well it wasn't the cam or anything in the engine, it was the fuel pump itself. It was stuck so hard I couldn't even move it using my vise and a rubber mallet !
So I took it all apart and with the help of some lubricant spray and the vise again I was able to remove the shaft. The fuel had turned to such a sticky mess it had seized the shaft to it's bore like it was welded. After spending some quality time with it I was able to clean it up and now it is all "right as rain" again !
Here's a picture of the disassembled pump.



This engine had been stored away for several years now. What is so annoying is I know better ! I should have properly prepped the engine for long term storage then but I didn't. So I just wasted about ten hours and a few cans of spray for something that should never had happened.
So just a reminder to all you out there storing your generators to properly prepare them. That means removing "ALL" the old fuel and putting some kind of lubricant spray in the fuel pump and allowing it to go through the injector/s .
Also all the old oil should be removed and fresh oil installed and circulated around. Still kicking myself.

 

[leedawg]

wow I would have never expected that either. So maybe I am just naive but what happened? WE have 2 1000 gallon diesel tanks on the vineyard and fuel sits in them for easily 1 -2 years between refueling and fuel in the tanks always seems fine.

So you had diesel sitting in the injection pump that degraded and became sticky? Ive never heard of this happening is it common? We have tractors we only run for about a week once a year and they sit the rest of the time. If I remember I get around to cranking them over and starting them up once or twice through the year. We have an old D4 cat that hasent been started for the past 4 years, just over Thanksgiving my dad and I decided would be a good idea to fire it up. Honestly to get the poney engine started was the nightmare there. Spent two hours getting the poney engine to start and run then threw it in gear and let it swing over the big diesel for a couple of minutes get the oil flowing then dropped the compression lever in and gave her a tiny shot of ether and away she went purring like a kitten. Id say getting the cat diesel started only took about 5 minutes the rest was the gas poney engine.

Hum given me a lot to think about perhaps worth purging out the fuel system if you are going to put a diesel away for an extended period of time. Maybe its a function of cold weather. Here in Northern CA cant really call our cold days that cold maybe dips down to 28 degrees F on the worst nights but during the day usually high 40-70. Would be curious what others have encountered with their sets.

Glad you got it sorted!

 

[Guyfang]

It can happen. Not all that often, but every once in a while. Like Greg said, once or twice a year, spin an engine over. Can't hurt, and will keep things loose. That's one of the reasons all the newer gen sets have a dead crank switch.

Greg, you just needed something to do, with all your spare time!!

 

[doghead]

Do you use fuel addatives?

 

[strycnine]

Both of my mep-016's had gummed up pumps when I got them. I try to turn them over every chance I get.

 

[rustystud]

It can happen. Not all that often, but every once in a while. Like Greg said, once or twice a year, spin an engine over. Can't hurt, and will keep things loose. That's one of the reasons all the newer gen sets have a dead crank switch.

Greg, you just needed something to do, with all your spare time!!

That's what the wife said !!!!
Still it has been cold and rainy here, and working outside makes my knee ache like crazy !!!!
What really makes me mad is I know better !!! I just didn't do it. Getting lazy in my old age I guess.

 

[rustystud]

Do you use fuel addatives?

That's another thing. I always keep "Pri-D" in my main 300 gallon tank. I just didn't use that fuel on the smaller MEP-501's though. I just used a 5 gallon fuel can with fuel from the local service station. Usually fuel will last over 5 years or more. Easily ! In fact I have used untreated diesel fuel that was over ten years old and no problems. I guess the stuff we get now is not the same as the good old stuff just a decade ago.

 

[rustystud]

wow I would have never expected that either. So maybe I am just naive but what happened? WE have 2 1000 gallon diesel tanks on the vineyard and fuel sits in them for easily 1 -2 years between refueling and fuel in the tanks always seems fine.

So you had diesel sitting in the injection pump that degraded and became sticky? Ive never heard of this happening is it common? We have tractors we only run for about a week once a year and they sit the rest of the time. If I remember I get around to cranking them over and starting them up once or twice through the year. We have an old D4 cat that hasent been started for the past 4 years, just over Thanksgiving my dad and I decided would be a good idea to fire it up. Honestly to get the poney engine started was the nightmare there. Spent two hours getting the poney engine to start and run then threw it in gear and let it swing over the big diesel for a couple of minutes get the oil flowing then dropped the compression lever in and gave her a tiny shot of ether and away she went purring like a kitten. Id say getting the cat diesel started only took about 5 minutes the rest was the gas poney engine.

Hum given me a lot to think about perhaps worth purging out the fuel system if you are going to put a diesel away for an extended period of time. Maybe its a function of cold weather. Here in Northern CA cant really call our cold days that cold maybe dips down to 28 degrees F on the worst nights but during the day usually high 40-70. Would be curious what others have encountered with their sets.

Glad you got it sorted!

From my personal experience diesel full usually lasts a long time before degrading. Of course the manuals still say to change out the fuel before storing. Usually I do what the manuals say. I think the fuel we are getting now is not as good as the older stuff. Remember there is only a small percentage of "sulpher" in the fuel today. That was the main lubricant for the fuel injector pumps and injectors. I think that was what bit me in the butt this time. That and not adding any good additives to the fuel I bought at the station.

 

[Floridianson]

Yea sitting up that long without a monthly warm up /test and additives not good. I add Opti/lube to the Trucks plus all the military generators that I had. I also double or triple up on the dose to the fuel. Wonder if the tarnish is the same as we see in the Deuce injection system? Myself on storage of one cylinder engines I also make sure the piston is on the compression stroke to keep the cylinder closed. If it is a multi cylinder then cap off the exhaust. Last Deuce engine I sold I warmed it up cooled down and then with the valve covers off I closed the open valves by backing off the open valves. That was because I figured it would sit up for years. Seems like a generator that you might need at a moments notice any day would be better kept not set up for storage but run at least every month. If I do feel like I need a backup generator for the house I will go with NG / propane. I got lucky as I have a home on both sides of Florida thanks Mom & Dad. If the power goes out on one side of the state I just drive to the other side.

 

[rustystud]

Yea sitting up that long without a monthly warm up /test and additives not good. I add Opti/lube to the Trucks plus all the military generators that I had. I also double or triple up on the dose to the fuel. Wonder if the tarnish is the same as we see in the Deuce injection system? Myself on storage of one cylinder engines I also make sure the piston is on the compression stroke to keep the cylinder closed. If it is a multi cylinder then cap off the exhaust. Last Deuce engine I sold I warmed it up cooled down and then with the valve covers off I closed the open valves by backing off the open valves. That was because I figured it would sit up for years. Seems like a generator that you might need at a moments notice any day would be better kept not set up for storage but run at least every month. If I do feel like I need a backup generator for the house I will go with NG / propane. I got lucky as I have a home on both sides of Florida thanks Mom & Dad. If the power goes out on one side of the state I just drive to the other side.

I forgot to add that I also use "Opti-Lube" in all my fuel. Though again in this instance I didn't add anything. I also agree with storing the cylinder at top dead center to keep the valves closed. This engine though was one of four that I have as spares. Like I mentioned earlier, I usually start them up on a regular basis but last year was so chaotic due to the remodel I forgot until recently.

 

[FarmingSmallKubota]

Old thread i know, but was hoping for some help. I have 3 MEP 531a i got the first one up at running, new fuel lines and filters and runs great. the next one was missing a few parts but between the last two everything thing is complete. The problem seems to be that the fuel pump just will not pump i took the pump apart and cleaned everything i could see reinstalled according to the TM no dice. i pulled the pump out of the other non running machine and still not getting fuel. What could i be missing here. The fuel shut off is turned on just to get that out of the way.

 

[Guyfang]

What you need to really do is start your own thread. This one is old, and titled MEP-501 Fuel Pump seized. A new thread bring clarity to the whole problem. And you can change the title, if you want.