Autostart vs manual push button start on 10kw

[amphi_sc]

I've noticed that when I use the dash or bedroom toggle button to start my 10kw Onan that it cranks 5 to 7 times before catching whereas it seems to immediately catch with the Autostart on the first crank revolution. I.e. I never notice it starting to crank over, it just seems to immediately catch and run.  Why is that? Is the Autostart circuitry doing something different than the dash or bedroom start/stop toggle switch? ... fuel priming? less voltage drop to starter?

[Venturer]

My guess is that it is preheating the intake air like our Tiffin did for cold starts before it engages the starter. You could try preheating manually for 10 seconds to see if it makes a difference. 

Edited December 10, 2023 by Venturer

[Ivan K]

Doug is right, with Onan generator selected, the AGS will preheat glow plugs for 15s before attempting to start. You can do the same manually. 

[amphi_sc]

14 minutes ago, Ivan K said:

Doug is right, with Onan generator selected, the AGS will preheat glow plugs for 15s before attempting to start. You can do the same manually. 

How do you do that?  When I press the toggle it indicates something (fuel pump priming???) for about 2 seconds before the starter engages.  What's the trick for 15 secs of glow plugs?

[96 EVO]

16 minutes ago, Ivan K said:

Doug is right, with Onan generator selected, the AGS will preheat glow plugs for 15s before attempting to start. You can do the same manually. 

Nice!

I never knew that 👍.

Just now, amphi_sc said:

How do you do that?  When I press the toggle it indicates something (fuel pump priming???) for about 2 seconds before the starter engages.  What's the trick for 15 secs of glow plugs?

Hold the stop side of the switch for 15sec.

[Venturer]

What Ben said. It's a rocker switch. Push the top and hold it. Then push the bottom for start. You should always do it when the OAT under 40 degrees. Saves the starter and quicker starts. 

Edited December 10, 2023 by Venturer

[96 EVO]

Ha, I didn't solve anything..... That was Ivan!

[amphi_sc]

1 hour ago, 96 EVO said:

Hold the stop side of the switch for 15sec.

Thanks.  I just tried it ... holding the bottom of the toggle switch for 15 seconds (timed via the neighboring Aladdin clock screen) and then pushed the top of the toggle to start.  It flashed for about 2 seconds as before and then the starter engaged ... and fired off on the third revolution ... with no stuttering or smoke as would normally happen on a cold morning after being cold sosked overnight in the 30's.  On another morning I may try holding the bottom of the toggle for a little longer to see if it will start on the first or second revolution as Autostart seems to do.  I like starting quicker without all the smoke and rough running for 15 to 20 seconds as it would previously do ... I guess clearing all the extra diesel from the longer cranking cycle.

It reminds me of old M$ Windows having to press the Start button to shutdown. 😉

[Ivan K]

The 2s delay on start is correct, it does the same thing with AGS start. 

[timaz996]

40 minutes ago, amphi_sc said:

Thanks.  I just tried it ... holding the bottom of the toggle switch for 15 seconds (timed via the neighboring Aladdin clock screen) and then pushed the top of the toggle to start.  It flashed for about 2 seconds as before and then the starter engaged ... and fired off on the third revolution ... with no stuttering or smoke as would normally happen on a cold morning after being cold sosked overnight in the 30's.  On another morning I may try holding the bottom of the toggle for a little longer to see if it will start on the first or second revolution as Autostart seems to do.  I like starting quicker without all the smoke and rough running for 15 to 20 seconds as it would previously do ... I guess clearing all the extra diesel from the longer cranking cycle.

It reminds me of old M$ Windows having to press the Start button to shutdown. 😉

Cranking over a few rotations lets the oil pump pickup some oil. So do the preheat but a few crank rotations is better for the first start in the morning.