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Topic: Fast Idle Set (Read 856 times) previous topic - next topic

Fast Idle Set

I learned from Dave M. when here one time that I could set the normal, operating, idle on the smart wheel using the res/set buttons and I reported that earlier here on the Forum.  Even Mark Harvey told me he had forgotten the trick so I thought it good to mention on the Forum.  Quite a few replied to say that they did not know of this and appreciated it. Setting low idle

SO, I am adding this that is new to me, from simple trial and error.  My high speed idle was a bit low, around 900 rpm.  So I just gave it a try.....Hit the cruise button to move it into high idle.  Then I tried the Res and Set buttons and sure enough, I could raise the high idle to what I wanted, about 1050 rpm.  Nice to know.

Mike
Mike
2001 U320 4010 Build 5878 (Gus)
Wrangle Unlimited Toad
Nacogdoches

Re: Fast Idle Set

Reply #1 –
Would be really handy. Does anyone know what models/engines this works on? NA for our '93 DD. Mechanical DD had one but not electronic.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Fast Idle Set

Reply #2 –
I have the King Cruise unit in Forrest.  It has infinite settings.  The process:
1. Turn cruise on.  2.  Select Set button.  3.  hold res button until you get to the rpm you desire.  4.  hold set button to reduce rpm to desired rpm.  5.  hit brakes or cruise off button to cancel high idle.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Fast Idle Set

Reply #3 –
Quote from: Pierce & Gaylie Stewart –
Would be really handy. Does anyone know what models/engines this works on? NA for our '93 DD. Mechanical DD had one but not electronic.
Pierce
Pierce: I have a '91 with the 6V92 like yours, and the cruise control doesn't give me the high idle either - is there any way that you know of to get a temporary high idle on these DD's?
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Fast Idle Set

Reply #4 –
In the factory seminars, we were taught to never idle a 2 cycle Detroit for any length of time so every morning as soon as we pulled the apparatus outside, we hit the fast idle button and it gave us 1000 rpm. Was air operated and just moved an arm on the rack to bring it up to speed. My bus was the same. After pumping at a fire, the engine would have low oil pressure at idle and possibly would not supply enough oil in a straight stream to go up into the hollow piston crown and cool it. The same would apply to our rigs after climbing long grades and stopping at the summit.

Now with the electronic engines, it might be done using the cruise control like some of the others. The problem would be wiring it to release if you touched the brake or shifted into drive. If the fast idle was at 1000 rpm and the coach was headed downhill, the engine could easily overpower the service brakes even with the brake pedal to the floor. As it is now, I have to shift into neutral heading down our long steep driveway or I can't get it to stop.

I know some DDEC Detroits do have a fast idle and even have a control to vary the rpm but I can't find much more information. Other forums discuss it but no schematic yet.

Pierce

Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Fast Idle Set

Reply #5 –
@Peter @Pierce My manual mentions the fast idle option but don't think mine has it. I've tried using the cruise control to activate but no luck. :(

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Fast Idle Set

Reply #6 –
Works great on my 03 U320.  David
David & Lou Ann Bouchard
Summer: Mount Vernon, Ohio
Winter: RiverBend Motorcoach Resort  LaBelle, Florida
2003 U320 38' Build #6174 "Willie"
2013 Cadillac SRX Toad
MC #17151 FMCA #F431393

Re: Fast Idle Set

Reply #7 –
Worked on our 92 U280 300 Cummins. Seems like it also worked on our 91 Grandvilla 3208.  On those I think we pushed the "resume" to increase idle speed.
Rick & Rhonda
2003 U320 4220  Build #6199
Was
91 36' GV 300 Caterpillar, 92 40' U280 300 Cummins, 97 36' U295 300 Cummins, 2002
U320 450 Cummins
(Guess we're hooked)

The selected media item is not currently available.

Re: Fast Idle Set

Reply #8 –
I believe the TRICK is to wait til you have air up.  Mine will not work until air comes up then you use the resume switch to increase RPM.  In fact if you fool with the resume without air pressure when air does come up engine will race.  To shut off you turn the cruise off, if you don't you can't get the Allison to engage.
Gary B
 

Re: Fast Idle Set

Reply #9 –
Quote from: Gary Bouland –
I believe the TRICK is to wait til you have air up.  Mine will not work until air comes up then you use the resume switch to increase RPM.
It appears that features and operation may vary among different vehicles.

I use fast idle in order to get the air pressure up. Cruise control works fine to set a fast idle.

Start engine; Press "Cruise Control On;" Press "Set;" Hold or repeatedly press "Resume" until engine speed is appropriate (900 +- RPM works for me)

Engage the service brake to release the cruise control.

King cruise control, air throttle, Cummins C8.3-325 engine
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX