TQG MPU failure - How common?

[cbisson]

So as I continue to stock up on spare parts for my 2 802a generators, I've gotten to the MPU on my target list. Realistically, how common is it for these to fail?

Thanks all

 

[Coug]

I would say it's not that uncommon for them to fail.
From what I've seen, it's the same basic MPU as the Generac liquid cooled standby generators (I'm a Generac Tech) and replacing the MPU is one of the more common reasons I have to work on them.

 

[robertsears1]

On my 804a, it worked fine until one day it didn’t. While cranking, no white puffs from the exhaust as if it wasn’t getting fuel. Went to the logic tree and none of that worked. Should have started with the magnetic pickup (MPU). It had some crap stuck to the end. Reinstalled, adjusted, and it worked fine. Later on, something ground the end down and it stopped workng. Put on a new one. My 804b has never had a problem and seems more robust. If you have an issue where it seems to not be getting fuel but the tank actually has fuel in it, suspect the MPU until proven otherwise.

Robert

 

[Light in the Dark]

Ive never encountered one I have had to replace due to fault. I have had to replace them due to being missing though. For whatever thats worth.

 

[jamawieb]

Never seen one fail. Ive had to clean or adjust a few, even that is uncommon.

 

[cbisson]

Ive never encountered one I have had to replace due to fault. I have had to replace them due to being missing though. For whatever thats worth.

If you've gotten sets with the MPU missing that suggests that a replacement was needed somewhere and your set was the donor.

 

[cbisson]

Looks like I'll have to add a couple of these to the stash.

Thanks all for your feedback.

 

[Light in the Dark]

A likely scenario.... also likely that folks looking to DRMO out sets remove items to render them not working. I'm going through an 'unserviceable' tagged 803 right now. Missing the VR fuse, missing the battery fuse, nipped wire to oil pressure sender, rigid fuel lines disconnected and metering pumps clocked closed. A lower hour decent condition reset machine at that.

 

[Guyfang]

OK, I have seen more then a few fail. BUT the biggest failure was always, operator/mech "Knobdicking". For those of you who are new to Knobdicking, it means:

1. "Adjusting" them for no reason.
2. Not reading the TM for the proper testing, adjusting and reinstallation of the MPU.
3. Not properly tightening the lock nut.

These three reasons are 95% of the reason there are MPU faults. All result in no signal, or a ground off MPU end.

I did not list "problems". Problems are:

1. Dirt, trash and other "impure" things on the end of the MPU.
2. Broken wires.
3. Failure to set ones Meter to AC volts when "testing".

But as long as you test, remove, clean, reinstall, adjust and retest right. The MPU will last a long time. I still would have one in my spares.