MEP-804B Starting issues

[Darren allen]

MEP-804B I had a problem getting it started after purchasing turned switch to start and only click sound from relay, finally started after hours I don’t know why it decided to start, started multiple times that day after a week of not starting it went back to doing the same thing and haven’t started since . I would appreciate some help with this issue thanks.

 

[Scoobyshep]

Are you comfortable and or competent with a voltage meter?

On the back of the starter there's two large studs one is always live with 24 volt that goes to battery the other one goes to the motor you're also be a little wire on the back of the starter that's the trigger. Have a helper hold the switch and start when it fails to crank and measure the voltage on these three wires to ground. This will help determine whether it's a starter issue or a controlling issue

Sent from my SM-S908U using Tapatalk

 

[Scoobyshep]

MEP-804B I had a problem getting it started after purchasing turned switch to start and only click sound from relay, finally started after hours I don’t know why it decided to start, started multiple times that day after a week of not starting it went back to doing the same thing and haven’t started since . I would appreciate some help with this issue thanks.

Just noticed youre in Lakeland, Im near altimonte, If you get completely stuck I could find my way down there.

 

[Darren allen]

Just noticed youre in Lakeland, Im near altimonte, If you get completely stuck I could find my way down there.

I would appreciate it because I have no idea what I am doing with this I recently move to wauchula a few days ago. I have had a chance to do the check as yet.

 

[Darren allen]

Are you comfortable and or competent with a voltage meter?

On the back of the starter there's two large studs one is always live with 24 volt that goes to battery the other one goes to the motor you're also be a little wire on the back of the starter that's the trigger. Have a helper hold the switch and start when it fails to crank and measure the voltage on these three wires to ground. This will help determine whether it's a starter issue or a controlling issue

Sent from my SM-S908U using Tapatalk

Good morning, positive stud 24V and stud to starter 2.8MV trigger wire 2.8 MV while held to the start positio.

 

[Retired-Tired]

My MEP-804B had a similar situation last week. It started and ran for several times with the over-speed trip activating when it wanted to. I would reset the over-speed trip switch and it would start right up again. Finally, it wouldn't crank at all. I was puzzled because I had a set of new batteries in the unit. I started diagnosis by reading up on several of the posts on Steel Soldiers and was able to decide to remove the MPU (magnetic pick-up) off of the flywheel housing. Well, it was covered by 1/4" of rust and filings. There is a procedure to follow and I re-installed the MPU accordingly to procedure. It started right up! I believe my situation was that my generator was stored outdoors and not run for a number of years, allowing rust to build up on the flywheel. Cranking on the flywheel allowed so much build-up of rust on the MPU that the MPU didn't allow voltage to be made and sent to the fuel solenoid on the back of the injector pump allowing it to start.

I hope this helps. This web site helped me a lot with posts just like this.

My next issue is for a new thread......

 

[Ray70]

My MEP-804B had a similar situation last week. It started and ran for several times with the over-speed trip activating when it wanted to. I would reset the over-speed trip switch and it would start right up again. Finally, it wouldn't crank at all. I was puzzled because I had a set of new batteries in the unit. I started diagnosis by reading up on several of the posts on Steel Soldiers and was able to decide to remove the MPU (magnetic pick-up) off of the flywheel housing. Well, it was covered by 1/4" of rust and filings. There is a procedure to follow and I re-installed the MPU accordingly to procedure. It started right up! I believe my situation was that my generator was stored outdoors and not run for a number of years, allowing rust to build up on the flywheel. Cranking on the flywheel allowed so much build-up of rust on the MPU that the MPU didn't allow voltage to be made and sent to the fuel solenoid on the back of the injector pump allowing it to start.

I hope this helps. This web site helped me a lot with posts just like this.

My next issue is for a new thread......

Interesting, I have an 806 at home ( belongs to a customer ) doing the same thing. Haven't had time to diagnose it, but will check the MPU once I get a chance!

 

[Guyfang]

The MPU has caused more problems in the MEP-8** family of generators then any other part. And more MPU's have been destroyed due to not reading the TM then two computers could total up, in 50 years. When the MEP-0** gen sets went to the Electronic Governor Control, we never had these problems. Once set up properly, we NEVER, EVER, had to fool with them again.

 

[Scoobyshep]

The MPU has caused more problems in the MEP-8** family of generators then any other part. And more MPU's have been destroyed due to not reading the TM then two computers could total up, in 50 years. When the MEP-0** gen sets went to the Electronic Governor Control, we never had these problems. Once set up properly, we NEVER, EVER, had to fool with them again.

One company I worked for had these boats powered by a 4 cyl cummins. They started basing their PM on hours vs calendar so the hour meters became important. These were driven off of the tach signal from the MPU. we discovered some were loosing hours. The very long discovery on that was the meter would run forward while under speed but backwards at idle. The MPU signals were bad due to improper setup. One mechanic would install till bottomed then backout the other would do similar while running and listen for the grinding noise. At that point the MPU became the electric shops problem and mgmt bought us a portable o-scope to set them to a known correct frequency range.