BCM Community

Hi all

My MC-5a was converted to an air throttle by the PO. (8v-71)  what is involved in add a fast idle solenoid (air or electric) on to my coach. I know I don't need it for ac, but I am old school enough to want it for the better oil pressure when sitting and idling with warm oil.

Thanks again to this great data base.

--Mike


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The fast idle isn't part of the throttle system at all (unless you go the route of adding a cruise control that can be set up as a fast idle).  The fast idle system replaces the buffer screw.  It has a couple of components.  It has an air cylinder with a large spring in it, a push rod that extends out when activated and pushes on the idle control lever inside the governor.  It adds the force of it's spring to the idle spring, creating the fast idle which is then under the control of the governor so it maintains speed somewhat regardless of load.  The air cylinder is activated by a Skinner valve - electric solenoid activated air valve - from a switch on the dash.  The switch has some interlocks so that you can't have fast idle on unless the parking brake is set.  There is a second Skinner valve which controls a throttle lock air cylinder.  That is used to lock the throttle control on the governor in the closed position so that it is impossible for the throttle to activate when the fast idle is on.

Now for me the cost and fuss of adding this system would far outweigh the benefits, which are basically none unless you have factory air conditioning.  There is little reason to idle the engine for long enough to cause any harm unless you are running the AC compressor, etc.  You could arrange for a pedal stop and a brick, too, for not quite so much money...   :o

Brian

Like Brian said the fast idle has nothing to do with a air throttle if you have Jakes somebody removed the fast idle and replaced it with the standard Jake buffer switch just another opinion 

Any idea where to find the parts to enable both the jake buffer switch and the fast idle on an 8V71?

  - Chris

Look in the spare tire section of this board. luvrbus has what you need.

I went the cheap route and used the buffer for Jake brake. For fast idle, use my King Cruise control. I too have air throttle. Good Luck, TomC