MEP-005 Fuel Injection Pump

[Memphisdoug]

I'm trying to get a MEP-005 running and am having problems with the fuel injection pump. There is fuel being delivered to the pump but it doesn't appear to be sending fuel to the injectors when I loosen a line to check. I have figured out there is an electric shutoff solenoid on the top of the pump. When I apply power to one of the terminals of the solenoid directly from the battery I hear it click. There is also a lever on the side of the pump that is not connected to anything and is free to rotate back and forth. From the service manual, it appears this may be a shutoff lever. If it is, I don't know what position is shutoff and what is run. Can anyone help out with suggestions on getting the injector pump to pump?

 

[Memphisdoug]

Bumping this back up in the list. I'm still looking for some help if anyone can provide it.

 

[leedawg]

Did you ever get this working?

I am having the exact same problem with My MEP 005a. Fuel is being delivered up to the injection pump. I have cracked open the bolts that go to the injectors and have the lever you speak of on the right all the way back towards the control panel of the unit. I crank it over and there is no fuel coming from the bolts that I cracked open on the pump leading to the injectors. When I open up the inspection window on the injector pump fuel starts running out of the window until I disconnect the fuel line to the pump. I took out the bolt on the bottom that says out right below the fitting where the fuel line goes in. NO fuel came out then when I cranked it over it sprayed fuel out of this port so I put the bolt back in. Still no fuel from the injector lines. I too checked the solnoid with 24v and it clicks on and off. I opened up the throttle wide open and still no fuel coming from the injector lines.

Is there anything else that should be done to prime the pump or test it? Or am I pretty much SOL and looking at a new injector pump to get this thing running? Thanks for all the help appreciate it.

Lee

 

[PeterD]

... I have cracked open the bolts that go to the injectors and have the lever you speak of on the right all the way back towards the control panel of the unit. ...
Lee

1. Top of lever to rear of engine, or bottom of lever to rear of engine? If you got it backwards by accident that will result in these same symptoms.

2. Check, carefully, the fuel return lines from the injection pump, especially the check ball. If the fuel return is blocked, it will not run.

3. Ensure that the solenoid is energizing. Monitor the voltage at the solenoid to ensure there is not a problem with the electrical control system. Then apply 24 volts (with a fused jumper wire) to the solenoid and listen to see if it clicks.

 

[leedawg]

Solinoid is functioning I wired it directly to the batteries and hear a click each time I put the wire on and off. Still no fuel.

The fuel coming into the injector pump is gravity fed from the day tank through the last fuel filter. It is not under very much pressure and just kinda flows out of the hose not very fast though.

I took the return lines off from the T fitting at the top of the injector. Should I be seeing fuel coming out of this fitting? Sounds like there is a check valve under this fitting that I need to clean possibly because you state that it will not work if there is no fuel coming out of the return lines on the fitting.

Thank you so much pete for you help.

Lee

 

[Memphisdoug]

You say the fuel at the injector pump is just gravity fed? Does that mean the fuel pumps are not working? It should be under pressure. I got the generator I was working on running. I ended up going around and around the fuel system making sure I was getting pressure to and out of the injection pump with the fuel pumps working. I believe the on position for the shut off lever on the injection pump is rearward- if there was a cable to it you would pull on the cable to turn it on which seemed backwards to me. It's been awhile since I worked on the thing or had it running.

 

[Isaac-1]

I am fairly sure your generator has a Stanadyne / Roosa Master DB series (maybe DC series) injection pump, it should run with fairly minimal inlet fuel pressure (gravity fed), but I am not sure just how minimal, the common symptom of a clogged return line is that it will run for a minute or so then die when return pressure builds too high. I suspect something is wrong inside your pump and you will need to have it rebuilt by a good diesel injection shop, typically rebuilds run $400-$500 on DB series pumps from most local shops, mail order shops run $100-$150 less, although be aware there are some less common D series variants that may cost more, I had a DC series one that ran $650 plus extra parts at a local shop a couple of years ago.

Ike

p.s. does yours show any signs of "coffee grounds" through the window, if so the rubber on your fly weight carrier is breaking down which may clog the pump.

 

[leedawg]

Alright I have solved the injector pump problem. I think I got lucky. Ike you are correct mine is a standyne pump. I pulled the window as you said and clean fuel poured out of it.

I removed the top cover where the solenoid is. I set the flywheel to 20 degrees and pulled the pump off engine. I inspected the levers inside of the top cover on the pump. I noticed that the lever closet to me and at the back of the pump did not move when I moved the actuator arm back and forth. I put some penetrating oil on it and worked it back and forth a bit and it finally freed up and now functions very smoothly back and forth. I think it was locked in the no run position so it would not let fuel into the injector pump.

I installed the pump again onto the motor. (This was sort of challenging) It was hard to get the shaft seal to go back into the pump barrel I oiled it up heavily with 3 and 1 oil and worked it around the barrel so the cup fit into the barrel and sort of twisted it back and forth as I worked it down the shaft. Pump engaged the slot and I lightly bolted it up to the motor. Rotated the crank shaft around by hand to the 20 degree mark again and aligned the lines in the fuel pump window.

Bolted the pump in place and hooked up the fuel lines Cranked the motor over and noted fuel shooting out of all six holes on the pump so success so far. Now I have to hook up all the injector lines and crank it over and keep my fingers crossed it starts. Will report back

Here are some pictures of what I did.

On another note fuel guage is not working removed sender unit looks okay old but okay. Float is intact. Tested resistance and noted that it is continuous and does not change when i move the float up and down.

Anybody know how to run test on the fuel guage?

Thanks again Lee.

 

[PeterD]

You say the fuel at the injector pump is just gravity fed? Does that mean the fuel pumps are not working? It should be under pressure...

Uh, no, it is gravity feed to the injection pump. The circuit is: main fuel tank, Fuel pumps (series), strainer, filter, solenoid, day tank. Day tank is non-pressurized. From the day tank to the final filter (gravity feed) to the injection pump. From the Injection pump via the fuel return line (and from injectors) back to the day tank.

Straight gravity feed, no pressure into the injection pump.

When the day tank (which holds about a gallon) is full, a float switch shuts off the fuel solenoid. Should there be a malfunction, there is a secondary drain high in the day tank should it overfill, and that drain leads directly back to the main fuel tank.

I've omitted the auxiliary fuel input and selector valve from this description.

 

[319]

I have the same pump (and I think the motor is the same) on my shop trailer. Check valve was clogged and gave me fits until I figured out it was the cause. After sitting for a few days it would start and run for a few minute's then die. After trying to restart, it would crank and fire but not run. Ended up punching the glass ball out of it and cleaning it real well. Runs like a champ now!

 

[leedawg]

Thanks for the replies Peter and 319.

Tomorrow I will check that check valve for sure. So Success the motor finally started now that the injector pump is putting out fuel. Fired right however im having some different problems now that it is running.

The first is it does not always shut off when flip the switch to the off position on the panel. Or it will very slowly decrease in engine speed until it finally dies and stops completely were talking over a 30 to 40 second period not 3-5 seconds.

However if I go flip the lever where the governor is supposed to hook to on the precise sets It will kill it right away so I figure it must have something to do with the spring loaded lever inside the pump maybe just needs to be exercised more.

The second problem which appears to be a much larger problem is the motor does not run evenly. I've never had one of these sets before so perhaps this is normal. I do have an MEP-003a and it stays pretty locked in at 60 hz once the throttle is set and engine is warmed up it maybe varies by 1-2 hz under load but stays pretty stable.

This thing when I try to set it to 60 hz I find it wanders down to 57 hz all the way up to 63 back and forth and there is no load at all on the motor (perhaps that's the problem no load) I find it very sensitive to the throttle when I twist it a little bit its almost way to high and then it fluctuates around a bit. Motor sounds like its running really well its not smoking at all so that's a positive I suppose.

I took a short little video so you could see what I mean. Watch the Hz gauge on the set and you can hear the motor changing speed all on its own.

Is there no governor on these sets? The 003 has a centripetal style governor what tells this thing to give it more fuel when there is a heavy load on the set?

[media]http://www.youtube.com/watch?v=Jx3KAl919ro[/media]

 

[Isaac-1]

There is a flyweight type governor inside the injection pump, your photo looked like there was rust on the fuel cut off shaft from when you had the injection pump top removed, if so the weights on the governor may also have rust on them causing them to stick. Also the knurled knob on the injection pump controls stability, did you turn it ?

Ike

 

[Memphisdoug]

Uh, no, it is gravity feed to the injection pump. The circuit is: main fuel tank, Fuel pumps (series), strainer, filter, solenoid, day tank. Day tank is non-pressurized. From the day tank to the final filter (gravity feed) to the injection pump. From the Injection pump via the fuel return line (and from injectors) back to the day tank.

Straight gravity feed, no pressure into the injection pump.

When the day tank (which holds about a gallon) is full, a float switch shuts off the fuel solenoid. Should there be a malfunction, there is a secondary drain high in the day tank should it overfill, and that drain leads directly back to the main fuel tank.

I've omitted the auxiliary fuel input and selector valve from this description.

That's interesting information. The generator I was working on (donated to the fire department from the DNR) didn't work that way. The fuel pumps always ran and appear to provide pressurized fuel to the injector pump. I'm betting some mechanic changed something in the fuel system over the years so that it no longer works like above.

 

[leedawg]

There is a flyweight type governor inside the injection pump, your photo looked like there was rust on the fuel cut off shaft from when you had the injection pump top removed, if so the weights on the governor may also have rust on them causing them to stick. Also the knurled knob on the injection pump controls stability, did you turn it ?

Ike

Hum, The knurled knob just looked like it wanted to be played with. I actually did turn it a couple of times. I do not recall which way. This was back when I was trying to get fuel to come out of the injector pump. So what does the knurled knob actually do. Is one way more stable and the other less stable? Sort of an adjustment for the gov inside of the fuel injector? Would you guys recommend running any fuel additives through it for an hour or so like an injector cleaner of sorts or anything like that?


Thanks Lee

Yeah the fuel system is gravity fed after the fuel pumps take the fuel up to the day tank.

*An update I searched through the manuals and only noted one mention of the knurled knob on the injector pump under the parallel operation provisions test. It states to adjust it so that fq droop is only 1.5 hz from 60hz. my knob is backed all the way off so that it is actually hitting the metal behind it perhaps I need to spin this knob in some? Thanks again ike appreciate the help and knowledge to my questions.

 

[Isaac-1]

Somewhere in the back of my head I seem to recall the suggested starting position for the knurled knob being 1.5 turns out from fully screwed in, this may be wrong. One other thought, I assume this version of the Stanadyne pump has 2 levers on the outside (one on each side), one is the speed control, the other is the external manual fuel cut off, there is also an internal fuel cut off that operates using the top mounted solenoid which you already mentioned. In most generator applications I have seen the external fuel cut off lever is tied in the on position, this lever is designed to be either fully on or fully off, however you can get strange engine speed issues if it is at a midpoint.

Ike

p.s. I found a reference to the knurled knob, screw in for more droop / lower sensitivity, screw out for less droop / more sensitivity, of course if you get it too sensitive you may see hunting.

 

[leedawg]

Okay well wanted to give an update. Sorry I did not post yesterday but ran out of time and did not get time to work on the unit. I spent several hours today though messing around with it.

I took the top off the injection pump and felt the linkages inside where all the fuel sits the main throttle linkage was a little sticky in a couple of spots. I drained the fuel out of the pump through the inspection window and shot a ton of liquid wrench penetrating oil into the the top and worked the mechanisms back and forth. I shot liquid wrench down into the pump area and cranked over the motor a bunch to work the liquid wrench into the pump and hopefully the governor as well. Reassembled it and started it back up.


Ran great for a few minutes then all of a sudden died. I remember somebody somewhere saying something about the glass check ball in the T. So I took that off again and sure enough there was gunk in it again and I had cleaned it out really well but I think there is crap floating around in the injection pump.

I did notice a bunch of debris down in the bottom of the top cup where the linkages are which I cleaned out with q tips.

Any way put it together again and started it up ran again for a bit but shut down on its own. Took the T off again and sure enough plugged up again. I went to the auto parts store and bought a T fitting and pipe nipple. Threaded it and hooked it all back up. Started it up and it ran for about 45 minutes no problems.

The RPM's dont seem to be hunting near as much as they were in the previous video I will try to take another video of it again tomorrow.

I do notice now however when I throw a load at it or unload it hz varies by about 1.5 to 2 hz and does not really correct from that unless I correct it manually with the throttle.

Perhaps I need to play with the knurled knob some more. I spun it all the way in and backed it off 1.5 turns form all the way in so perhaps I need to back it off a little more and see if that helps the droop hopefully without hunting.

Oh I also drained all the fuel and put new fuel in with Standyne performance fuel tx into the mix and mixed it twice as strong as recommend and let that run through it for 45 minutes. I just wish I had a load bank to load this thing up more to work the motor a little harder. I am planning on doing the single phase conversion to it and will hook it up to the house and turn the AC on in the house.


So again I have never owned one of these how much hz variance from 60 is normal for loads coming on and off with these sets. I realize its not the precise model but I would think it would hold it within about 2 hz from 60 +/- but perhaps more variance on these things is normal or my gov is not compensating enough yet?

Thanks again for all the help guys its been really helpful.

Lee

 

[Isaac-1]

I still suspect the rubber parts in the injection pump are breaking down and this problem will not go away until you replace them.

Ike

 

[leedawg]

I still suspect the rubber parts in the injection pump are breaking down and this problem will not go away until you replace them.

Ike

AKA im looking at a rebuild in my not to distant future most likely

I sort of had the same sinking feeling in the back of my mind. I priced it out everywhere around here has quoted me about 700 dollars starting and possibly could go up depending on which parts are damaged Will test it more tomorrow when I hook up a decent load to it and see what happens.

 

[Rickety Bones]

Im having the same problem with mine, I will try this and replay back with the results, thanks for the pictures, they make understanding better

rick

 

[leedawg]

Im having the same problem with mine, I will try this and replay back with the results, thanks for the pictures, they make understanding better

rick

Yeah if you have any questions feel free to ask. I will try to answer them with my limited experience.


Another update. Today I feel as though I have made a lot of headway toward getting this unit restored to what it is supposed to be. I hooked the unit up to the main panel today at the barn and put it under load. Seemed to hold around 58-62 hz no problem varying a bit with load. If I tweak the throttle it will hold 60hz no problem and varies up and down bout 1 hz depending on loads coming on and off line. I then decided it was time to see what she could really do. I dropped in the 200 amp breaker to the house and the other well. Loaded the unit right up. Amp meter as you can see in the video is running around 90 amps on both legs to the panel. I turned the Dryer on and the oven and had the 8 ton AC running along with 4 refrigerators and a freezer. Turned my air compressor on in the barn and had the AC unit in the barn running as well as some space heaters and the charger for the forklift.

I ran the genny for about an hour and half under this load and it held the hz within about 1 to two hz of 60 hz plus or minus depending on the load. Im not sure if this is normal for these units but seems to be good enough for all the stuff I am running and the electric motors did not seem to mind the minor variance in freq.

Engine running really clean no smoke water temp around 160. Checked all the wiring with the infrared thermometer and did not notice any hot spots.

After an hour and a half it ran out of the 4 gallons of fuel I put in it. Low fuel light came on and it shut down on its own. So that is working at least. Hopefully the injector pump will not need to be rebuilt but only time will tell who knows.

The only thing that is not working now and im not really sure how to go about fixing it is the percent power meter. You can see in the video the whole time it just reads 0 on the meter. The amp meter is working great but the percent power meter is not. Im going to post in the 004a conversion the same question and see if anybody knows how to fix it.

Thanks again for all the help guys.

lee
[media]http://www.youtube.com/watch?v=9zD10OnEKRw[/media]