Air Throttle slow to respond

[Jay Darst]

I have had a slow responding air throttle since purchaseing my Bird
3 years ago.

Have dismantled the air cylinder at the engine compartment and it
was a little slimy, but not too bad.

I read in a recent post from Ralph with regard to Larry Watsons air
leak question, that there is a air pressure regulator in that
provides air to the air throttle and cruise control.

My question- If this regulator were either set too little or too
much air pressure, how would that affect the air throttle system?

Too little make it slow to respond? and too much make it too quick?

Thanks!

Jay Darst
85PT40
Springfield, IL

[George Lowry]

Jay,

You are correct. When I first converted to an air throttle on my GM bus
conversion, I did not know about the need for reduced pressure and fed
full pressure to it. It was so sensitive that you could not hold a
steady rpm. I reduced it to 60 psi and it worked great. A friend had
used an adjustable regulator, such as used on a paint spray rig, located
at the driver's station so he could regulate the pressure. When leaving
a toll station or inspection station, he would lower the pressure down
to about 25 psi so he would not smoke nor be too loud, then crank it
back up when on the road.

George Lowry
'06 Alpine Apex - Formerly '95 WBDA 4203
Spearfish, SD enjoying the warmth of Indio, CA



Jay Darst wrote:

>I have had a slow responding air throttle since purchaseing my Bird
>3 years ago.
>
>Have dismantled the air cylinder at the engine compartment and it
>was a little slimy, but not too bad.
>
>I read in a recent post from Ralph with regard to Larry Watsons air
>leak question, that there is a air pressure regulator in that
>provides air to the air throttle and cruise control.
>
>My question- If this regulator were either set too little or too
>much air pressure, how would that affect the air throttle system?
>
>Too little make it slow to respond? and too much make it too quick?
>
>Thanks!
>
>Jay Darst
>85PT40
>Springfield, IL
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>Yahoo! Groups Links
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[Ralph L. Fullenwider]

HI Jay:

No, with a short explanation. The air throttle is controlled by the air
throttle valve ( gas pedal) then flows to a double check valve to the
throttle cylinder. The lower air pressure from the pressure reducing
valve/regulator insures that with the cruise control set, you can increase
speed by pushing the foot pedal, then return to the modulated air from the
cruise control and the set speed. Then when the break is pressed, the air
from the inversion valve is vented through an exhaust port on that valve.
So with the throttle being slow three items are the high hitters to check.
1 cylinder 2. Air throttle valve and 3 the double check valve.

When the break is applied, it sends 120 psi to the inversion valve closing
part of that valve and also closes part of the foot throttle and exhausts
the built up air pressure at each point to and exhaust valve, which also
exhausts the air pressure from the cruise control ( the air have been shut
off electrically by the break signal: at the Bendix, but at the same time,
if the cruise control has not been shut off electrically, when you hit the
resume button, the Bendix remembers the setting to the valves and returns
the 80 to 90 psi to the set speed once again) since the inversion valve has
now blocked the exhaust port shutting off the air from the break pedal.

Ralph

At 03:12 AM 2/13/2006 +0000, you wrote:
>I have had a slow responding air throttle since purchaseing my Bird
>3 years ago.
>
>Have dismantled the air cylinder at the engine compartment and it
>was a little slimy, but not too bad.
>
>I read in a recent post from Ralph with regard to Larry Watsons air
>leak question, that there is a air pressure regulator in that
>provides air to the air throttle and cruise control.
>
>My question- If this regulator were either set too little or too
>much air pressure, how would that affect the air throttle system?
>
>Too little make it slow to respond? and too much make it too quick?
>
>Thanks!
>
>Jay Darst
>85PT40
>Springfield, IL
>
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>
>

Safe travels,

Ralph and Charolette Fullenwider
Duncan, Oklahoma
580-574-2768
Ralph's RV Solutions
http://home.swbell.net/rlf47/index