MEP-806B won't start.

[MAA907]

My local small fire department purchased 2 MEP-806B's from Federal Property Surplus. Both were not running and had fluids drained. 1 unit only had 6 hours on it, in hind sight this should have been a sign. The other unit has 6965.2 hrs on it.
1. Filled up all fluids, new filters and batteries.
2. Unit with 6 hours will turn over (crank) but not run (start).
3. 2nd unit engine was locked up, found out later the exhaust cover was missing and it had been rained on . Pulled turbo out gallon of Marvel Mystery oil in exhaust and valve cover. So now have an expensive paper weight and parts machine. May put time into it later.
4. So on low hour unit ended up running a jumper from S1 switch 24volts to Fuel Actuator. After reset and little starting fluid started right up, only problem no voltage.
5. Went throught trouble shooting guides, followed Magnetic Pickup procedure for removal, cleaning, installing and testing. No voltage from MPU of 1 to 1.5 volts as manual suggest.
6. With or without jumper I get Backplane (28 LED 5 red) lite up. Low voltage to CMOS.

I have read through the post and have tried several of the suggested fixes. I am not having any luck, any help or pointers would be greatly appreciated.

 

[MAA907]

My local small fire department purchased 2 MEP-806B's from Federal Property Surplus. Both were not running and had fluids drained. 1 unit only had 6 hours on it, in hind sight this should have been a sign. The other unit has 6965.2 hrs on it.
1. Filled up all fluids, new filters and batteries.
2. Unit with 6 hours will turn over (crank) but not run (start).
3. 2nd unit engine was locked up, found out later the exhaust cover was missing and it had been rained on . Pulled turbo out gallon of Marvel Mystery oil in exhaust and valve cover. So now have an expensive paper weight and parts machine. May put time into it later.
4. So on low hour unit ended up running a jumper from S1 switch 24volts to Fuel Actuator. After reset and little starting fluid started right up, only problem no voltage.
5. Went throught trouble shooting guides, followed Magnetic Pickup procedure for removal, cleaning, installing and testing. No voltage from MPU of 1 to 1.5 volts as manual suggest.
6. With or without jumper I get Backplane (28 LED 5 red) lite up. Low voltage to CMOS.

I have read through the post and have tried several of the suggested fixes. I am not having any luck, any help or pointers would be greatly appreciated.

Without jumper unit will not start.

 

[Guyfang]

My local small fire department purchased 2 MEP-806B's from Federal Property Surplus. Both were not running and had fluids drained. 1 unit only had 6 hours on it, in hind sight this should have been a sign. The other unit has 6965.2 hrs on it.
1. Filled up all fluids, new filters and batteries.
2. Unit with 6 hours will turn over (crank) but not run (start).
3. 2nd unit engine was locked up, found out later the exhaust cover was missing and it had been rained on . Pulled turbo out gallon of Marvel Mystery oil in exhaust and valve cover. So now have an expensive paper weight and parts machine. May put time into it later.
4. So on low hour unit ended up running a jumper from S1 switch 24volts to Fuel Actuator. After reset and little starting fluid started right up, only problem no voltage.
5. Went throught trouble shooting guides, followed Magnetic Pickup procedure for removal, cleaning, installing and testing. No voltage from MPU of 1 to 1.5 volts as manual suggest. (set will not start without the AC voltage here. The MPU tells the govenor to send voltage to the actuator. What did the MPU look like? Take a picture of it, the bottom, and post it. Test it IAW the TM.
I would try for 2 VAC, when adjusting it. Do be careful installing it, or you WILL be buying another. Your jumper will allow the set to start, because you are jumping around the engine governing system. So be careful.)
6. With or without jumper I get Backplane (28 LED 5 red) lite up. Low voltage to CMOS.

I have read through the post and have tried several of the suggested fixes. I am not having any luck, any help or pointers would be greatly appreciated.

 

[MAA907]

Thanks for the reply.
The MPU looked fine other than a fine metal and dirt. Cleaned it, reinstalled per TM.
Tested per TM. No Voltage.
I have removed the MPU from the second unit, I will clean, install and test tomorrow.
I do not leave the jumper connected, mainly to make sure was not problem with fuel system and to charge batteries.
I will let you know how it goes, we are expecting Hurricane Zeta tomorrow it may change my plans.

Thanks again.

 

[Guyfang]

Did you test the MPU for ohms?

 

[Guyfang]

You should get 800-1100 ohms.

 

[MAA907]

To be honest I believe I did but that was last week. I will recheck tomorrow if I can. I originally pulled it off last week. Yesterday I went through I think every thread I could find and try those fixes. I removed every connector plug and checked for corrosion and applied di electric grease (silicon). Even the two main plugs off the back panel. That was a pain. I traced voltage through S1 to Emergency Stop to I/O (heartbeat board) ? So this morning I started from scratch in the TM and ran trouble shooting, when I got to MPU, that is when I made my post and started removing MPU from other unit. I do not have TM with all my notes with me. It looks like the neither unit has had the MPU removed before, I had to cut (alter) the thin metal guard so they could be removed. These photos are from high hour parts unit today. I will clean it and ohms test it tomorrow.

Thanks again for your help!

 

[Guyfang]

Getting to the two plugs behind the I&O takes years off your life!

 

[MAA907]

You should get 800-1100 ohms.

I used two different meters on both MPU. Low hour unit was 218 and 216 ohms, still installed ( not sure if that matters). Other unit MPU ohms was 220 and 218 removed from unit. I will go back and reread threads I thought I saw where someone used a locally sourced automotive mpu. I tried calling manufacture and only got voice mail, maybe they will call back.

 

[MrShawn305]

I used two different meters on both MPU. Low hour unit was 218 and 216 ohms, still installed ( not sure if that matters). Other unit MPU ohms was 220 and 218 removed from unit. I will go back and reread threads I thought I saw where someone used a locally sourced automotive mpu. I tried calling manufacture and only got voice mail, maybe they will call back.

There is a thread somewhere that lists the MPU part number that can be had from the local Freightliner (I think) dealer. I will see if I can find it.

 

[MAA907]

There is a thread somewhere that lists the MPU part number that can be had from the local Freightliner (I think) dealer. I will see if I can find it.

Thank you. I have been looking on past threads for nearly and hour. The more i dig the more threads I find.

 

[Guyfang]

If you PM member 155mm, he may be able to shed some light on how he found one for the 805A set.

 

[MAA907]

If you PM member 155mm, he may be able to shed some light on how he found one for the 805A set.

Thanks, I found the thread. The threads are like rabbit holes. The more you look, the more you find.

 

[Guyfang]

 

[MAA907]

I have been away from the generator for a week or so. I did order a speed sensor that was used by someone else for a MEP-805B in another thread. It came in yesterday and the threads are the wrong size. I will send it back for a refund. Guess I could have drilled out hole and retaped but it would have required me to remove more of the sheet metal to access. The part was only $26.95 plus shipping no big loss. I jumped back on internet found original manufactures ?? spec chart for part number MSP-6728. The one I found was MSP-6728C, only difference it comes with the mating connector. The price was $59.00. We will see in a few days if it will work. Hope this helps someone. I have attached picture of original MPU, the 1st one I ordered (wrong size for my generator), and the new one I hope I found that will replace the original.

Thanks again to everyone that has helped, it is greatly appreciated.