MEP-004A parts, and problems

[joshgar8]

Hey guys,

It seems like it has been forever, but I finally got my problems solved on my gen set. There was something FUBAR in the voltage regulator. I took it to several places to get it repaired without any luck. I ended up replacing the regulator and that solved all the problems with the HZ gauge and high voltage. Thanks for your help through the process of getting it back up and going.

Josh

 

[Enginerd]

I just bought my MEP-004AAS from GovLiquidation and Picked it up in Utah at the base. Got it home, checked the oil and fluids, checked the batteries, wiring, plugs, etc. The unit starts and runs but only for a few seconds then shuts down. What am I missing on the startup?

 

[Enginerd]

Ok, a little more info. I saw that it was dripping fuel, so I started checking things. Found that the aux fuel inlet cap was not even finger tight and had been leaking. I also filled the tank just in case the gauge was off. Still will not stay running more than a few seconds after it is up and running. It starts easy and quick but it is the staying running that is the issue. No trouble lights that I can tell either. They all work but one and I will get a new bulb tomorrow.

 

[PeterD]

Ok, a little more info. I saw that it was dripping fuel, so I started checking things. Found that the aux fuel inlet cap was not even finger tight and had been leaking. I also filled the tank just in case the gauge was off. Still will not stay running more than a few seconds after it is up and running. It starts easy and quick but it is the staying running that is the issue. No trouble lights that I can tell either. They all work but one and I will get a new bulb tomorrow.

What is the oil pressure gauge reading? You must hold the start/run switch in the start position until you both have oil pressure, and the unit is generating power (the volt and frequency meters register approximately the correct values, they may be off by a bit.)

It sounds like you don't have oil pressure, or perhaps the sender/wiring is bad. Other possibilities include a problem with the fuel return check valve on the injection pump (a small ball which tends to get crudded up and sticks closed.) or something else in the fail-safe system shutting you down.

Did you do a lights test to test the indicator lamps, and if so do all light? What lights are (still) on when it starts?

 

[Enginerd]

Ok. Did a lights check and all come on in test mode except for over current. I don't get a fault when it shuts off. Oil pressure comes up to at least 40 but it still shuts down. I will check the check valve next and see if it will stay running with the battle switch flipped. I suspect it could be the oil switch but will check the others as well. It is showing that there is power being generated.

 

[Enginerd]

Question. Where on the injector pump is the check valve at? I see where the like ties onto the pump, it has the return to the day tank on one side of the T and the return from the injectors on the other. Is the ball between the T and the pump?

 

[Enginerd]

Oh, PeterD. My problem sounds just like the one you are posting on in the MEP-004a starting issue thread with 212Sparky. Will look at the fuel lines tomorrow.

 

[jamawieb]

Question. Where on the injector pump is the check valve at? I see where the like ties onto the pump, it has the return to the day tank on one side of the T and the return from the injectors on the other. Is the ball between the T and the pump?

It's right there as you described above, remove the T and it's in there. It's just a glass ball the sometimes get full of junk and won't let the pressure release from the pump.

 

[Enginerd]

Ok. Checked the check valve and cleaned it really well and made sure it was working. No problems there. Decided to start at the beginning, or close to it. Bleed the filters and got fuel out of the one from the day tank to the injector pump. went to bleed the strainer and nothing. So I pulled the screens off of the pumps and OMG what a mess. They were both plugged so I cleaned those and figure I will have to do it again soon. May have to flush the tank as well. Put them back together, primed the unit, and fired it up. It ran for longer than I had ever had it running but didn't see voltage or frequency on the gauges for the output voltage. Once I get the fuel system cleaned, I will tackle electrical output.

 

[jamawieb]

Make sure you hold the start switch up for a while when starting. The Gen set has to flash to get electrical output. By holding the toggle swith in the start postion after the engine starts, is what flashes the set.

 

[Enginerd]

Ok. Update. As I said, I cleaned the pump screens. They were bad. Replaced all the fuel filters with new. Found that there were two check valves on the pump return line. Strange. Recleaned pump filters just in case. Found that the first paper filter after the pump screens was missing the spring and spring cap so basically it was doing nothing. Let the pumps run again and they ran for a couple of minutes. Bled the air out of the filter after day tank until no more air. Bled air at injector pump as well while electric pumps were on.

Still has the problem with running then running out of fuel. Cannot get day tank drain to drain anything which concerns me. Once it runs for 20a seconds or so, and voltage comes up as well as frequency, it just runs out of fuel. If you try restart, it tries but no go. If you wait a minute or two, it will run again.

Next step is to remove day tank and flush? Thoughts?

 

[Enginerd]

The last text was from my phone so sorry if it was not completely clear. So, all the filters have been changed, found a spring and spring cap for the first paper filter so it will seal now and actually do something, removed the redundant check valve. get fuel out of everywhere I should except for the day tank drain. I even drained a gallon or so from the main tank just in case.

I figure that there is still a restriction somewhere. Yes, I hold the start switch up and it still dies simply because it runs out of fuel. The only other thing I can think of is to remove the lines, all lines, one at a time on both ends and blow them out. Then do the same thing with the day tank drain as well as the tank itself.

If the solenoid was not functioning, would it even start and run as long as it does?

Each step I take gets me closer and you guys have been a great help for sure. Please be patient with me on this. I have done a lot of work on gas engines but have not done much on diesel engines. I know the theories behind them because I am an engineer but the hands on part I am still working on.

Again, thanks for all the help so far.

Just had a thought. I do not see any type of float that would shut off the fuel from from the electric pumps into the day tank. Is that right? I take it that the pumps shut down when the level sensor in the day tank senses that the tank is full and kills power to the pumps until the level drops. If it didn't work that way, then with the tank vent line removed and the pumps in battle mode or whatever it is called, fuel should flow out of the overflow/vent line on the side of the day tank. Am I all wet on my thinking?

 

[PeterD]

...
I figure that there is still a restriction somewhere. Yes, I hold the start switch up and it still dies simply because it runs out of fuel. The only other thing I can think of is to remove the lines, all lines, one at a time on both ends and blow them out. Then do the same thing with the day tank drain as well as the tank itself.

If the solenoid was not functioning, would it even start and run as long as it does?

...

Just had a thought. I do not see any type of float that would shut off the fuel from from the electric pumps into the day tank. Is that right? I take it that the pumps shut down when the level sensor in the day tank senses that the tank is full and kills power to the pumps until the level drops. If it didn't work that way, then with the tank vent line removed and the pumps in battle mode or whatever it is called, fuel should flow out of the overflow/vent line on the side of the day tank. Am I all wet on my thinking?

(the famous were this my problem answer... )

1. I'd consider trying the following: The injection pump is gravity fed, I'd rig up a temporary fuel tank and see if it keeps running. I'm going to say that I think it will stall. I know you checked the check-ball but did you check all the fuel return lines--I want to re-emphasize that a blocked or seriously restricted return line will cause exactly what you are seeing which is why that keeps coming up.

2. Yes, it might start if the solenoid is pulling in but then releasing for some reason. But this would be unusual, IMHO.

3. The float is inside the day tank. The way the fuel shuts off is with the solenoid valve above the day tank. The pumps continue to run, that's normal.

4. For power: you can flash at any time the engine is running as well, by simply pressing the start/run switch to start. There is an interlock that prevents the starter from engaging once the engine achieves a certain RPM level. I (and I think everyone else) simply press up to start and hold it there until the frequency/volt meters indicate about 60 Hz and 120 volts. I always leave the throttle at the position where it was when I shut down (I never adjust or anything until it is running and generating power, then I fine tune it to 61 Hz.)

So reconfirm the fuel return lines as being clear. If you have fuel dribbling from the hose into the injection pump, you should not have fuel problems--test by letting it fill a bottle (say a pint or so) and if it does that OK, then the fuel system to the pump is OK.

 

[Enginerd]

No good

Ok. I spent the morning doing the following:

Remove the return line from the last injector to the T. Remove all 3 return lines between injectors. Remove the return line from the T on the IP to the T at the solenoid valve. Remove the line from the day tank to the secondary filter. Remove the drain from the day tank.

Each line I blew through with good carb cleaner to make sure it was clean and free from debris. I also blew through each T on the injectors as well just to make sure they were free flowing. Since I could not get liquid to drain from the tank drain, and because I saw sludge coming from the line to the IP, I started cleaning it as well.

I removed the level probe and cleaned it. i then cleaned the day tank and it was a royal pain. There was a lot of stuff in the bottom. It is now sludge free. I reassembled the hoses and tightened then. Then I recleaned the pump filters as well got everything reassembles. I turned the power on and let the pumps run on Battle Short until I heard the solenoid close and the pumps slowed. I then opened the line from the filter to the IP at the IP connection and allowed it flow for 30 seconds to a minute just to make sure the fuel was free flowing.

I started the unit which ran just above idle holding the start switch. Eventually, the engine started to slow then died. The whole time I had the switch held in the start position.

Now I am at a loss as to what to do.

Edit 1: It would run for a while if idling but only a few seconds if running full out. It still runs fine, then starts to slow, then shuts down. I do not here any electrical clicks, it just slows and dies.

I have not rigged up a different tank yet. Had to step back and not deal with if for a few of it might find its way off a cliff......

 

[PeterD]

What is the throttle control (that knob below and right of the instrument panel) set at?

 

[Enginerd]

I have ran it at idle and it ran for a minute or so. I have had it out so it was running at 2" out and at 3" out or where the voltage was about 220V. It ran a few seconds.

It still seems like a fuel problem so I am going to remove the elbow on the fuel feed to the pump and check it. I will do the same with the check valve too. Will the engine run without the check valve in the IP? I will try and measure the voltage to the IP as well to make sure I am not getting only partial power to it.

When I pulled the fuel line off at the pump, it would let fuel through at a steady rate. I am not sure how to describe it but it was much more than a drip but not like it was under pressure. It looked about right for something with only a few inches of static head pressure. I am wondering if it is something internal to the pump or if maybe the injectors themselves are not allowing the extra fuel to return.

 

[Enginerd]

I just talked to my friend that is a diesel mechanic and was a M1-Abrams tank mechanic during the first Gulf War and he is wondering if it is internal to the IP or if I am loosing voltage for some reason at the pump. Will check those.

Just pulled and checked the inlet strainer on the pump. Right where the supply line ties onto the pump, the elbow screws into a fitting that is actually a strainer assembly. I removed mine and cleaned it, it was dirty. When I pulled the fuel line, the fluid came out at a good rate. I drained the entire day tank in a couple of minutes. I think my flow to there is good so I think it might be internal to the pump.

 

[jamawieb]

In the IP inlet (where the fuel line goes in) there is a screen inside there. You just take the inlet fuel line off and unscrew that elbow and the screen is part of it. I wonder if that is clogged since your day tank was nasty.
Also in reference to your question about the check valve, the ip will run fine without the check valve in it. I knocked mine out with a punch and it runs perfect. I hope you get it running, I had a bunch of problems with my first MEP-004A but it is a great learning experience.

 

[Enginerd]

Thanks for the info. I cleaned the screen, it was bad but not horrible. I may try knocking the check ball out of my valve because some idiot in the past actually installed a second one on it so I now have a spare.

 

[PeterD]

Remember fuel feed is gravity from the day tank to the injection pump. So if the day tank is filling/filled then the fuel pumps and all that pre-day tank stuff should be OK. The cover on the injection pump can be removed, be careful to keep everything spotlessly clean if you decide to remove it--clean the pump well before removing the screws.

Also, make double sure the throttle is not set to idle! It needs to be set at running throttle position when starting.