MEP-003A won't stay running

[CobraBrat]

I can start the engine with starter fluid (glow plugs rusted off), but after running well for 45-60 seconds, it seems to bog down and then die. I am having some difficulty moving around fast enough, but starter fluid does not seem to keep it going once it starts to die.
Fuel filters are new.
Air filter is new.
Tank is clean and has a new cap (I left it loose to prevent vacuum).
Oil pressure is 40psi
The fuel shut off solenoid is working properly (stays retracted until the engine dies)
Diesel verified at injector pump and at all injectors.

I have some ideas:
1) bad fuel pumps
2) not getting enough air (not likely)
3) engine freezing up due to poor lubrication

I know I have a cracked spacer block under one injector, but it runs OK with the crack (does blow a little out of the crack). I don't think that it the problem (fix it when it will stay running)

Any help will be appreciated.

Neil

 

[ctfjr]

a simple thing to eliminate is the oil pressure safety switch - you can jump that

I had a bad one on my 003 but that won't account for any bogging - just dieing

 

[CobraBrat]

ctfjr
My understanding is that if the oil pressure switch is bad, then it will open the circuit to the fuel shut off solenoid and the solenoid will then kill the engine. However, the solenoid is staying energized, so the oil sending unit must be working properly.

 

[ctfjr]

ctfjr
My understanding is that if the oil pressure switch is bad, then it will open the circuit to the fuel shut off solenoid and the solenoid will then kill the engine. However, the solenoid is staying energized, so the oil sending unit must be working properly.

That is correct - so long as the switch stays closed

 

[steelandcanvas]

Look at the under-side of your fuel tank cap. Is it in the vented or non-vented position? IIRC, there is a little metal tab you turn 90 degrees to vent or un-vent. Let us know what you find out.

 

[CobraBrat]

SteelandCanvas
As I said, I left the cap loose so that there was no question about venting. But yes, I had it set to open.

 

[storeman]

Are you getting fuel returned to the tank when unit is running and when you are priming the fuel system?
Jerry

 

[212sparky]

check your return line in the IP. mine was full of crud on the check valve. i replaced my on my MEP-004 and it runs great now

 

[CobraBrat]

Storemen
Fuel is returning going back to the tank. However, if you run the pumps for very long, they seem to develop alot of back pressure because they run slower and slower and nearly stop. If you let the pressure drop off, they run fast again.

212Sparky
I will check the supply and return lines. Based on what I said to Storeman above, that may be the problem.

 

[steelandcanvas]

SteelandCanvas
As I said, I left the cap loose so that there was no question about venting. But yes, I had it set to open.

My bad, you did say that. I'll keep thinking though.

 

[CobraBrat]

I have cleaned the fuel line and check valve to the injector pump, but that was not the problem.
I have shorted across the high temp switch to make sure it was not cutting off the engine, but that was not the problem.

I have noticed that as the engine runs, it has more and more blow by around one or both of the center cylinders' injectors. So I think that what is happening is that when the engine is cool, it has enough compression and will start and run. However, as the engine heats, the crack/blown gasket/whatever becomes larger and the cylinger loses too much compression and does not fire.

My theory is not correct if the engine will run on two cylinders. Does anyone know whether it will run on two cylingers?

 

[derf]

Is the solenoid shutting it down or something else? You can disable or remove the solenoid but make sure you know how to stop it if you do disable or remove anything.
If the solenoid is shutting it down then find out why. Low oil pressure switch? Overtemp? 24V charging circuit failing?
Edit: Looks like you eliminated the above.

If not, then check for fuel delivery failure.
Edit: You may have an injector stuck open or partially open and have a hydro lock type situation. I'd fix whatever is cracked and have the injectors tested.

It's either fuel or air, incoming or outgoing, probably that is bogging it.

 

[LuckyDog]

Storemen
Fuel is returning going back to the tank. However, if you run the pumps for very long, they seem to develop alot of back pressure because they run slower and slower and nearly stop. If you let the pressure drop off, they run fast again.

Had a similiar situation. On top of the IP, there is a fitting that connects the IP to the Injector Return lines and the hose going to the tank. It is NOT an ordinary fitting. Inside is a very tiny hole between the IP and the other two connections. Mine was plugged. A 0.025 inch drill bit will clean it out without removing any metal. After cleaning, my pumps ran strong. At first, I thought I broke something because they always did that REAL slow tick tock sound. Now they tick along a couple clicks per second.

I found that plugged fitting while rebuilding my IP. There is a fitting inside that is designed to break if the plunger get jammed. Mine was jammed from sitting so long. After I un-jammed it, the motor would do the "Run for a few seconds and quit" thing.

A LOT of these generators have IP issues from sitting so long.
So, check IP timing: Use the 1/8" pin in the screw hole method. THEN do the flow method. Mine was spot on with the rod, but WAY OUT A WACK with the flow method.

Since you have a compression leak at the injector, you need to fix at least that injector before you'll get to full power. (Yeah, I know you know that)

 

[CobraBrat]

Lucky,
Can you clean out the hole at the return line fitting with it on the engine or do I need to take it off and clean the IP to fix all problems?

 

[LuckyDog]

Should be able to do it on the engine. Don't know how good an idea that is. I am paranoid about getting dirt into the fuel system after the fuel filters. Tolerances are REALLY tight on fuel pumps. Maybe someone else will chime in.

I just know it is accessible while mounted.

 

[Speddmon]

I have cleaned the fuel line and check valve to the injector pump, but that was not the problem.
I have shorted across the high temp switch to make sure it was not cutting off the engine, but that was not the problem.

I have noticed that as the engine runs, it has more and more blow by around one or both of the center cylinders' injectors. So I think that what is happening is that when the engine is cool, it has enough compression and will start and run. However, as the engine heats, the crack/blown gasket/whatever becomes larger and the cylinger loses too much compression and does not fire.

My theory is not correct if the engine will run on two cylinders. Does anyone know whether it will run on two cylingers?

Sounds to me that you are on the right track. I doubt very much that the engine will turn the generator head and 2 dead cylinders. Sounds like a valve adjustment and compression test is in order for all the cylinders. Hopefully it's just valves and not broken rings or scored sleeves causing the compression loss.

 

[CobraBrat]

Well, I finally got it running. I started by replacing filters and cleaning and coating the fuel tank. Then when things just were not going well, I replaced two non-working injectors, a cracked finned injector spacer, a leaking head gasket, all of the rusted.non-working glow plugs, and the leaking fuel hose between the check valve and the IP. When it starts up, it misses and smokes heavily, but after it warms up, it does not miss or smoke. I'm not sure what the problem is now, but it runs, and that may be good enough for me at this point.

Thank you Jerry for all the help and good replacement parts.