Newell Gurus

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Hi All,

The winner for this round of resolution is Michael Day. House batteries were only charging to 10.5-11 Volts. Lots of great advice along the way. Thanks to everyone for helping me out. Special thanks to Tom for recommending O'Riley's (they did all the heavy lifting) and explaining some of the details of the electrical system, and to Richard for his sage advice on things to do (and not to do) during the install and the new tool in my tool box.
Last fall while on the road in warm country I started the generator to give us more air conditioning.  It would run for a while and quit.  It had been serviced < 1 month previously at Newell.  It turned out that it was low on coolant and has run fine ever since topping it off.
(03-22-2021, 05:42 PM)bestgenman Wrote: [ -> ]I certainly may be incorrect here but, I think Dave’s PT set had isochronous governing.  The stop solenoid is removed and replaced with an electronic actuator which acts directly on the fuel rack of the injection pump..  it has a spring pushing the rack to the no fuel position when power is removed.  It uses PWM when operating delivered from an engine speed controller.  The engine speed controller receives a signal from a mag pickup.   If Dave has a MPU, it is likely an Isoc governed engine.  I’m sorry if I’m rambling here...but it could explain some of the erratic operations.  They are very temperamental.  I remember Dario Framchiti’s coach (785) had one,  it came in here for repair and I removed the electronic portion and that stopped all the aggravation.

Would love to know more about the electronic portion you are referencing.  I have #789 w/ Powertech and the Fuel Stop solenoid is causing issues.  When i hook to strait 12v it opens/closes - when I attach back to the gen, it stays in the closed position, or opens briefly and shuts everything back down.  When its removed, the gen runs perfect and I can manually shut off by feeding a small straighthead to push the fuel stop.

Any info much appreciated Smile
I’m addressing what I think you are asking for.  
The isochronous governor is a steady state speed control regardless of load.  Most of our sets are droop governed.   There are three components to make up the system.  
1. Mag pickup.  Senses speed by counting the teeth on the flywheel generally. Generates a somewhat square wave.
2. Speed controller.  This receives the pickup signal , has power (12vdc), and converts to an output which feeds the actuator.  The signal is generally PWM (pulse width modulated). There are gurus here that can explain that better than I can.
3. The actuator.  It appears, on these engines, attached to the injection pump resembling the shut down/run solenoid.  It moves the fuel rack inside the pump adjusting fuel delivery in accordance with speed.

The common downfall is actuator sticking.  This causes erratic speed or no speed at all mostly. The fix is , replace the actuator.  Occasionally, the controller fails and this almost always results in no signal to the actuator.

Hope this is what you were looking for.  If not, I’ll take another stab at it!
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