Two Auction MEP-803A Starting Issues..... Different on Each unit.. HELP??

[Jayco36REQS]

I bought 4 auction MEP-803A's....

- (Unit #1) Added new fluids, filters, inspected the unit, fixed fuel return line, new batteries, 5-gal clean diesel... Dead cranked fine, no leaks, charged fuel system 4x with 30sec pause between. Then cranked it up with a shot of either in the air intake hose.. it fired right up... chugged a couple times, smoked a little, then purred along. It was spitting out black soot for a min or two... then cleared up. Looked for any leaks, and none found. Let it run 15 min or so. Checked 120v outlets and had stable 120v power on both.

Issue: After shutting it down to check oil and water levels.. I went to restart it, and now it starts then immediately shuts down with a low oil pressure warning light?? As soon as it starts, the oil pressure goes to 40psi... but the low pressure warniing light clicks on and the unit shuts down.

- (Unit #2) Same as above... new fluids, filters, fuel... Nothing appeared broken or wrong. Dead cranks fine, no leaks, charged fuel system.

Issue: When I try to start the system it starts to turn the starter then immediately goes dead. Fuel pump and everything disengages... I have to turn the master switch to off, then back on to fuel pump to get the aux or primary pump to run again... and as soon as I try to start it.. same as before.. clicks and starter starts to spin and poof... dead. It still dead cranks fine and normal speed.... so it's definitely not a starter issue.

Any ideas or thoughts would be GREATLY appreciated!! Thanks!!

- I'm going to tinker with (Units #3 & #4) tomorrow. REALLY hoping they are problem free... ugh lol

 

[Kenny0]

First unit, hold switch on start longer after unit starts, no it wont hurt anything. Oil pressure sender or connections could be bad. I think this has 2 senders, one for gauge and one for low oil pressure shut down. Second unit sounds like battery connections or connections to the engine, also make sure both batteries are good.

 

[Jayco36REQS]

I'll give it a try holding the start switch longer on Unit #1...

For Unit #2, the dead crank works fine and spins the motor over easily... Has two new batteries, and cables tested good for resistance. As I said, It's only when I try to start it.. it starts to spin the starter, then kills power to the whole system including both fuel pumps.

Has me stumped...

Ohh Also this is a rebuild system with a odd looking cap with pins on the Remote Monitoring Port...

 

[Daybreak]

Howdy,

Take a look here. Tobyhanna modified mep-803a assistance

 

[Kenny0]

Could this be a Tobyhanna rebuild? Good post for it here https://www.steelsoldiers.com/showthread.php?174636-Tobyhanna-modified-mep-803a-assistance . Sure sounds like a bad connection or contact in the switch. Could disconnect the batteries and cycle through all switch positions a bunch of times and see if that helps. Also check the pins on the cap and make sure they are making good contact. Check the above post if it has the Tobyhanna mod, last post tells how to remove it.

 

[Jayco36REQS]

Thanks guys... I'm going to remove the "new" Remote Monitoring Port, and put this Gen back to stock. Then see if it starts normal.

I'll update with some pics.

Thanks!

 

[Guyfang]

It's never a bad idea to post pictures before you start. Lots of people have sharp eyes and can tell you when they see something fishy.

Start the #1set normally. By normally I mean hold the S1 up longer. If that dosnt work, then try again, But do not release S1. Instead, flip up S7, then let S1 go. Does the set still run? Do you still have good oil pressure? If so, then turn it off. Then Disconnect one wire from the LOP and see if you can start it and it runs without the idiot light coming on. If the set still shuts down, the the fault indicator could be bad. And check your wires very carefully. The ends are often loose.

 

[Jayco36REQS]

OK... Unit #1 ... Held down the S1 longer and she fired right up, and ran fine. Ran it for 30 min. Temp at 185deg, 40+psi oil pressure, good power... Only issue is the AC voltmeter doesn't work at all. I shut the unit down, and it restarted no problem. Running smoother now.

Unit #3... Did the usual prep work.. Fluids, filters, etc.

Issues: When priming the fuel, the fuel pump was noisy, and never seemed to smooth out. I cracked the fuel line at the 2nd fuel filter, and air hissed out, then fuel. kept priming, but the pump still didn't sound right. I pulled the fuel return line off the end of the fuel rail, and a tiny stream of fuel was shooting out... I went ahead and cranked it over, and shot of either and if fired right up... but immediately sputtered and died. I cranked it again and shot of either and it fired up easily again... this time I shot a 2nd shot of either and it ran for a second then died. So basically, it's not getting fuel.

Any tips? I'm good with cars, but these old diesels I'm still trying to learn...

 

[Light in the Dark]

What setting do you have the large voltage reconnection switch set to, inside the operator control panel? Do you also have the voltage selector switch on the outside of the panel set to correspond to match with the interior setting? Might by why its not reading.

 

[Light in the Dark]

On the other set... how long are you letting the fuel circulate? Let the pumps run for a few minutes... let the entire system try to purge itself before you crank again.

 

[Daybreak]

Howdy,
Throw away the ether.

You are going to damage stuff.

Read the forums. Read the manuals.

After putting on new fuel/water filter, and fuel cartridge, leave it on prime and run a long long time. It has to fill up all that area.

Proper starting technique, turn to start and wait...wait...oil pressure is up, ok now release.

 

[Guyfang]

OK... Unit #1 ... Held down the S1 longer and she fired right up, and ran fine. Ran it for 30 min. Temp at 185deg, 40+psi oil pressure, good power... Only issue is the AC voltmeter doesn't work at all. I shut the unit down, and it restarted no problem. Running smoother now.

Unit #3... Did the usual prep work.. Fluids, filters, etc.

Issues: When priming the fuel, the fuel pump was noisy, and never seemed to smooth out. I cracked the fuel line at the 2nd fuel filter, and air hissed out, then fuel. kept priming, but the pump still didn't sound right. I pulled the fuel return line off the end of the fuel rail, and a tiny stream of fuel was shooting out... I went ahead and cranked it over, and shot of either and if fired right up... but immediately sputtered and died. I cranked it again and shot of either and it fired up easily again... this time I shot a 2nd shot of either and it ran for a second then died. So basically, it's not getting fuel.

Any tips? I'm good with cars, but these old diesels I'm still trying to learn...

Set #1.
Use your multimeter to measure what voltage you have on the AC volt meter terminals.


Do follow LITD's advice about S-6 and S-8, in message #9.

Do exercise the S-6 and S-8. Do it while the set is turned off. If the switches feel like they are hard to turn, full of grit and small bowling balls, then cleaning of switches in called for.

Set #2.
Do follow LITD's advice about S-6 and S-8, in message #10.I am a fan of turning on the pumps. Crack the fuel line at every possible place in the system. There could be crud in the system. If the pump still runs irregularly, check the plug on the electrical fuel pump. Check to see if the fuel system is tight, (if you crack the system at every possible opening, then it should be tight!) I am also a fan of using Teflon thread tape on every connection.

Do look in the TM, on how to check the output of your fuel pump.

Crack the lines to the injector pumps, (input side) getting good fuel flow? Then crack the lines at the injector pumps, (output side) getting good flow? If you have good fuel flow up to there, then pull the injectors, and reconnect them up, so you can see if you are getting fuel from the injector pumps and through the injectors.

Have you shown a GOOD flashlight into the fuel tank to see if you have trash in there?

Oh, yeah. If you keep using either, you are going to have to start a new thread about how you destroyed your engine, and are now rebuilding or replacing it.

 

[Jayco36REQS]

Ok... Newest Update:

Unit #1 - Power Switches are correct. Gives good power, but the AC voltmeter is still zero. Leads show zero as well.... I didn't see a troubleshooting path in the manual for the Voltmeter?

Unit #2 - Removed the Tobyhanna rebuild remote monitoring plug and wiring. It was very easy as when they did the mod during the rebuild, everything was just connected to factory terminals, or bolted the leads together and shrink-wrapped. So undoing it was straight forward and easy. Once I removed it and reconnected the leads, it fired right up, and purred like a kitten...

Issues:
1) Quick testing of the electrical plugs and terminals shows 22.5v on the 110v outlets, and L1/N, or L3/N Then 45v at L1/L3 I've never had a gen show less than 110v.. it either showed 110v or 0v

2) Volt adjust knob doesn't make any change at all and of course the AC volt gauge doesn't register anything.

 

[Guyfang]

Ok... Newest Update:

Unit #1 - Power Switches are correct. Gives good power, but the AC voltmeter is still zero. Leads show zero as well.... I didn't see a troubleshooting path in the manual for the Voltmeter?

If you had no voltage at the meter, then the meter is probaly good. Its not getting any voltage from S6. Can you read a wire diagram/schematic?

Unit #2 - Removed the Tobyhanna rebuild remote monitoring plug and wiring. It was very easy as when they did the mod during the rebuild, everything was just connected to factory terminals, or bolted the leads together and shrink-wrapped. So undoing it was straight forward and easy. Once I removed it and reconnected the leads, it fired right up, and purred like a kitten...

Issues:
1) Quick testing of the electrical plugs and terminals shows 22.5v on the 110v outlets, and L1/N, or L3/N Then 45v at L1/L3 I've never had a gen show less than 110v.. it either showed 110v or 0v

Maybe you didn't hold up S1 long enough to excite the main gen. Try holding the S1 up longer at the start. If that doesn't work, have someone help you, while doing it yourself, well, its best to have three hands. Anyway, use the multimeter. One lead on pin 7 of the S1, the other to ground. Start the set. Hold up the S1, don't let it go. Do you get 24 volts? If so, then check the FU2 fuse, next to the A1. If you get no voltage at the S1-7, then the S1 switch is bad, or hooked up wrong.

2) Volt adjust knob doesn't make any change at all and of course the AC volt gauge doesn't register anything.

a

 

[jamawieb]

Ok... Newest Update:

Unit #1 - Power Switches are correct. Gives good power, but the AC voltmeter is still zero. Leads show zero as well.... I didn't see a troubleshooting path in the manual for the Voltmeter?

Unit #2 - Removed the Tobyhanna rebuild remote monitoring plug and wiring. It was very easy as when they did the mod during the rebuild, everything was just connected to factory terminals, or bolted the leads together and shrink-wrapped. So undoing it was straight forward and easy. Once I removed it and reconnected the leads, it fired right up, and purred like a kitten...

Issues:
1) Quick testing of the electrical plugs and terminals shows 22.5v on the 110v outlets, and L1/N, or L3/N Then 45v at L1/L3 I've never had a gen show less than 110v.. it either showed 110v or 0v

2) Volt adjust knob doesn't make any change at all and of course the AC volt gauge doesn't register anything.

From glancing over the thread, it appears you have 120volts when the master switch is in the start position and as soon as you let it go, the voltage drops to 0 or 37volts. Is this correct? If so, more than likely the Voltage Regulator has failed and you will need a replacement.

 

[Jayco36REQS]

a

Ok, when I start with S1 and hold in start longer,
- I see the AC voltmeter show 220v,
- my meter plugged into the 110v outlets shows 110v

As soon as I let go of the S1 from start, it all drops to 22.5v

I checked pin 7 on S1, While holding S1 in Start, it shows 21.5v. ( Where is the FU2 fuse?? ) I see FU1

 

[jamawieb]

My bet is the voltage regulator.

 

[jamawieb]

Ok, when I start with S1 and hold in start longer,
- I see the AC voltmeter show 220v,
- my meter plugged into the 110v outlets shows 110v

As soon as I let go of the S1 from start, it all drops to 22.5v

I checked pin 7 on S1, While holding S1 in Start, it shows 21.5v. ( Where is the FU2 fuse?? ) I see FU1

FU2 is the voltage regulator Fuse I believe. I don't have the manuals in front of me now. Some models have the FU2 fuse and some of the older models do not. It would be located to the left of the voltage regulator mounted right beside it.

 

[Jayco36REQS]

OK... I got it working.

This unit has many items that look completely different than any of the other MEP-803A units I have, or have had. Apparently the FU2 fuse is a quick pull type of fuse holder, actually mounted against the A1. It didn't have a fuse in it at all!! ( Ok yes, I'm a dunce sometimes) But I've never seen a connector like this in any of my other Gens so it didn't register that it was a problem

So now the Gen is running fine, AC Voltmeter works perfect, Power is steady at 120v at the easy plugs, and between L1/N and L3/N, and 240v between L1/L3.

Thank you Guyfang for the troubleshooting tips!!! Your AWESOME!!

 

[Jayco36REQS]

Question... What size fuse is supposed to go into the FU2 holder? Right now I just have a piece of Aluminum tubing.. lol

For my other MEP-803A I'm keeping, I'm going to add this fuse to the A1.

Thanks again for all your help!!