C-9 cat will not fast idle

[Joe Rhea]

Dave:
I spoke with you on the phone awhile back about the fast idle problem.
Here is what the idle is doing:
I push the idle switch down once nothing happens, push it down a second time it will go to fast idle ( no in between ). As soon as I release the switch it returns to slow idle.
Also is there a easy way to check exhaust brake solinod I don't believe it is working. Light on dash comes on when activated.

[Joel Ashley]

Joe, to potentially help you out, readers will benefit by knowing what coach you have.  Most of us edit our Forum Profile or Signature fields to provide that information automatically with each of our posts.

I'll let Dave address your questions, but I will throw in that our (and I'd expect most) fast idle switch isn't "momentary", but rather pressing the rocker once in one direction keeps it down and fast idle on;  rocking it back keeps fast idle off.  The Jacob's "pac-brake" on our '06 Monterey C9 400 is readily accessed on top of the engine streetside from wardrobe and bedroom floor panels.  The butterfly on it should move freely when activated, but if not regularly used or lubed with special heat-resistant oil, such devices can seize up on owners.  I believe either the Jacob's or Pac-Brake websites can provide diagrams and instruction.   http://pacbrake.com/supplemental-brakes/prxb-exhaust-brakes/maintenance/

Joel

[Dale Walker]

Can't help you with the fast idle, switch, Joe, sorry, but I can tell you I had reason to believe the Pac Brake was not working. So after many shots of WD-40, pounding on it, prying, and trying to move it with everything from a Cresent wrench, and Channel lock pliers, my only recourse was to pull it off. Not a big deal, 2 clamps, and the hose, and it was in the bench vise where I could really work on it. What I found was the air cylinder was completely frozen. The butterfly was completely free, so googled it and ordered a new cylinder. $114.00. I put it back together, and it works good, and damn glad it did, on the way down to AZ.

[Dave Atherton]

Joe, you have low and fast idle but information is very inportant and helpful in a reply.
First question how cold outside that requires the low and high idle. Second what is your
Engine coolant temp reading ( thinking you may be in engine cold mode because if that
is the case, switch is working correct. ) Engine speed up with heui system depends what
Air/fuel is doing with ECM and engine water temp. Dave Atherton Retired Cat Mechanic

[Joe Rhea]

Dave:
Thanks for the reply. It doesn't appear that the temperature is a factor. I have tried it when the temp. was in the 80's and when it was in the 50's. In the past my procedure was to start the engine and wait for the oil pressure to stable out and then increase engine speed which I could do in increments until I reached operating temp. I will be moving the coach today to have the windshield rebedded and I will see if the idle works at operating temp.
On the pacbrake I don't have a wiring diagram to trace wireing to solinod. I would like to check it out electricaly as well as mechanical. Is there a relay I can jumper to activate?
2005 Monterey Lugna IV
C-9 Cat 400HP

[Joel Ashley]

Joe, refer to this Forum thread re. your exhaust brake:   http://beaveramb.org/forum/index.php/topic,4515.msg33955.html#msg33955

Joel

[Joe Rhea]

Thanks Joel
I wil see if I can find the proper wire
Joe Rhea

[Dave Atherton]

Joe Rhea, idle speed on caterpillar electronic engines is preset between 700 and 750 rpm.
If extended idle time is required, control engine rpm to 1000 rpm. Ensure that the coolant
temperature exceeds ( 180 DEG F ). Note: fast idle is program within range of 700 rpm to
top engine limit 1000 rpm. Fast idle requires an ON/OFF switch on dash. This goes on and
states this is a on/off switch only. Engine will reach normal operating temperature faster
When engine is operated at low rpm. This method is faster than trying to reach operating
temperature operating engine at 1000 rpm. Basic I do not understand your problem on
raising rpm via: Cat Engine Operations 01/05/2011 Dave Atherton Retired Cat Mechanic

[Joel Ashley]

The main reason many of us use fast idle at all is just long enough to more quickly pressurize low air tanks at startup, although I oft wonder if that really is any faster.

I wonder also if there is something haywire with the switch itself on Joe's panel:
"I push the idle switch down once nothing happens, push it down a second time it will go to fast idle ( no in between ). As soon as I release the switch it returns to slow idle."

Joel

[Dave Atherton]

Joel, that is possible with switch, my only thoughts engine warm up ( what little time
difference we are talking means nothing. My main point warm up engine, Allison trans,
mean while do a equipment check walk around etc. guess I feel qualified to make this
statement but each each there own. Many problems are over looked by rushing to get
moving for whatever reason. Dave Atherton retired Cat Mechanic.

[Joe Rhea]

Thanks Dave and Joel:
My switch is doing the same thing as Joel's. It is acting as a momentary in stead of a rocker. Knowing how it is supposed to function makes things a lot clearer.
Now I will try to address my pcbrake issue this morning. If anyone has a PDF drawing of the wiring of the pacbrack circuit I would appreciate a copy.
Thanks again for the help
Joe Rhea
finaltrade1@gmail.com

[Joel Ashley]

You misunderstood my post.  I was quoting Joe's initial statements.  My own switch works fine.

Joel

[Jim Edwards]

HI, My 2005 C9 "fast idle" switch is a momentary contact as well. If I press and HOLD it for say 10 seconds it will go up to 1200 RPM. If I hit it " momentarily" there seems little effect. I figured it was just a bit funky. So based on this post I decided to look it up in the manual and it states the following:

Fast Idle Switch:
Increases and decreases the idle of the engine in 25 RPM increments. There are limits to the idle
speed, about 700 to 875 RPM.

Which explained my problem

If this still gives you problems and your coach is equipped with a "Smart Wheel" the manual provides this alternate method to set/engage high Idle..

Another function of the smart wheel is to increase the idle speed using the "HIGH IDLE" feature.
To use the High Idle Feature:
1. With cruise control ON: To raise the idle, push the Set button. The idle will be raised
while pushing the button.
2. With cruise control switch ON: Push the Resume button once and the RPM will raise 1250.
Push Resume again, idle drops to 1000 RPM. Push and hold the Resume button, the idle
will raise to 1500 RPM.
3. Use cancel or turn the cruise control off to return the engine to normal idle.

I guess they differentiate between fast Idle and High Idle.

Just a thought that might help.