Reply
 
Thread Tools Display Modes
 
Old 10-15-2018, 08:24 AM   #1
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
No throttle

I have a TC1000 with a 5.9L 24V.
Engine starts and idles but there is not throttle. In other words pressing the accelarator pedal won't do a thing.
Front air reads about 40 psi and rear about 30.
I have not been able to identify any air leaks.

Is there a troubleshooting guide I can follow?
Tomas is offline   Reply With Quote
Old 10-15-2018, 09:10 AM   #2
Bus Geek
 
brokedown's Avatar
 
Join Date: Dec 2016
Location: St Petersburg, FL
Posts: 2,547
Year: 1997
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: Cummins 5.9
Rated Cap: 72
Your bus doesn't want to operate below 90-100 psi. if you have an air throttle it may not work until you've achieved operational pressure. You sure won't have brakes that low!
__________________
Keep up with us and our build!
Follow us on Facebook, Instagram, YouTube, and Twitter
brokedown is online now   Reply With Quote
Old 10-15-2018, 09:19 AM   #3
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
Correct. I do believe I have an air throttle.
Should I be checking for air leaks and whether the compressor is building enough pressure? Or are there other checks I should be performing?
Tomas is offline   Reply With Quote
Old 10-15-2018, 11:20 AM   #4
Bus Geek
 
brokedown's Avatar
 
Join Date: Dec 2016
Location: St Petersburg, FL
Posts: 2,547
Year: 1997
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: Cummins 5.9
Rated Cap: 72
when you shut your bus off, how fast does your 30-40psi turn to 0psi? if it empties fast you should be looking for leaks. If it stays at 40 for days then the compressor is not doing its job.
__________________
Keep up with us and our build!
Follow us on Facebook, Instagram, YouTube, and Twitter
brokedown is online now   Reply With Quote
Old 10-15-2018, 11:36 AM   #5
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
ok thanks. I am gonna check that.
Tomas is offline   Reply With Quote
Old 10-17-2018, 10:52 AM   #6
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
Ok I checked for leaks and couldn't find any.

The air pressure for both front and rear stays at around 30 psi for several hours before slowly dropping. If there is an air leak it is very small.

I checked the air drier and didn't find any leaks there. Same for the rear brake actuators.

What would be the next step? Check the air pressure governor? Whats the procedure for checking that? Do I remove the whole compressor with governor for that?
Tomas is offline   Reply With Quote
Old 10-17-2018, 11:54 AM   #7
Bus Nut
 
Mountain Gnome's Avatar
 
Join Date: Oct 2017
Posts: 382
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
Quote:
Originally Posted by Tomas View Post
Correct. I do believe I have an air throttle.
Should I be checking for air leaks and whether the compressor is building enough pressure? Or are there other checks I should be performing?
My 1999 TC1000 with a 5.9L 24V has an electric "throttle" pedal. But actually diesels don't have a "throttle;" there is never a restriction on the air going in. Only more fuel being added as you need more power. Are you saying the fuel pressure/volume injected into the motor at any given time is regulated by air pressure? I don't believe so. It is controlled with oil pressure.

Perhaps there is a safety feature that won't let you drive if your air is low (if yours is newer than mine) but I doubt it. I would look into the fuel pedal switch or its wiring
Mountain Gnome is offline   Reply With Quote
Old 10-17-2018, 01:27 PM   #8
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,125
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
gnome,


some busses, generally Rear engine busses with non electronic engines had a throttle that was activated by air pressure.. the way it worked is at the pedal you have an air valve that sends air pressure back to a spring loaded actuator.. the mnore air pressure, the more that actuator essentially activated what would have been the throttle cable. if the bus air brake system pressure was not up then the throttle would fail to operate. there should not be an air throttle on a front engine bus..



being electronic this one should be an electronic fly-by-wire.. make sure the wiring connector at your throttle pedal is plugged in securely and that none of the wires have been damaged or cut.. these wires should feed into a harness going to the Engine computer.. be sure the engine computer connectors are secure as well..

-Christopher
cadillackid is offline   Reply With Quote
Old 10-17-2018, 01:34 PM   #9
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,769
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
Not sure how you checked for air leaks.



Can you comment on that as you do have a few leaks I assume from reading this?


A spray bottle of water and dish soap is a priceless tool for chasing down leaks.
Spray down every fitting and every inch of hose, compressor fittings etc. takes some time sure but then you can make a plan to fix.

And it is fun watching the bubbles being blown.


John
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 10-17-2018, 01:44 PM   #10
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
I only listened for air leaks by crawling under the bus.
There could be air leaks but they are very small. Like I mentioned pressure for both front and rear air tanks remain at a constant 30 psi or so for several hours. Leaks cannot be the reason it's not building pressure.

I believe the accelerator/throttle on the TC2000 and TC1000s are locked unless operating pressure is reached regardless whether it's a front or rear mounted engine. I have front mount and there is an air valve marked "throttle" on the manifold above the tanks on the access hatch by the drivers side of the bus. The line has pressure right now but only 30 psi. I presume once 90 psi or so are reached that it unlocks or activates the accelerator pedal.
Tomas is offline   Reply With Quote
Old 10-17-2018, 03:00 PM   #11
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,246
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
See what the pressure is in the wet tank, the gauges on the dash don't read that. Opening the petcock on it with the bus running is a quick way to tell for air flow/pressure.

After that, find the governor and see if that is stuck causing the compressor not to run.

As far as air pressure and throttle issues, as said by others, the throttle is electronic and is completely seperate from the air system. I doubt the two problems are related.
Booyah45828 is offline   Reply With Quote
Old 10-17-2018, 08:03 PM   #12
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 1,652
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Air systems are not terribly complex ... though they can seem to be. You have:


1. Air compressor (and it's related governor, belt/gears, pulleys, etc.) The function of this is fairly straightforward. The governor's job is basically to turn the thing on/off, typically at 90/120 PSI, respectively.
2. Air dryer (on most systems, a few may not have this). The air from the compressor goes through this. Many have "cartridges" or filters that should be changed about once a year (and rarely are). The most common symptom of a failed air dryer is a failure to build up pressure (and usually accompanied by a very noticeable hissing of air from the dryer). Some designs are proprietary to the vehicle to which it's attached, but so-called universal fit designs work just fine in their place.
3. Air tanks. You'll have at least 1 "wet tank", fed by the air compressor, and at least 2 "dry tanks". Sometimes you'll have 1 tank with 2 compartments, or any combination the builder installed. There is often a "protection valve" which will feed the dry tanks once the wet tank reaches a certain pressure. If a tank looses pressure suddenly, this protection valve maintains pressure in the other system, giving you a chance to stop safely.
4. "Everything else". Air brakes, air-ride suspension, parking brakes (also called spring brakes), air-ride seat, gauges, warning lights and buzzers, brake-pressure sensor (the one that makes your brake lights work), and, you guessed it, everything else. The vast majority of this stuff is past a protection valve, basically meaning none of it will work until the system reaches the protection pressure, typically 60-80 PSI. An air-throttle (if you have one) will be on this circuit. Usually the only thing *NOT* on this circuit is the brake pedal, parking brakes, and gauges/warnings. The brakes *NEED* to work at all times, regardless of how much air is in the system.
Brad_SwiftFur is offline   Reply With Quote
Old 10-17-2018, 09:05 PM   #13
Bus Nut
 
Mountain Gnome's Avatar
 
Join Date: Oct 2017
Posts: 382
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
Quote:
Originally Posted by Tomas View Post
I have a TC1000 with a 5.9L 24V.
Engine starts and idles but there is not throttle. In other words pressing the accelarator pedal won't do a thing.
Front air reads about 40 psi and rear about 30.
I have not been able to identify any air leaks.

Is there a troubleshooting guide I can follow?
What year is your bus? My 1999 TC1000 5.9L 24V will respond to the accelerator pedal with no air in the system (after bleeding the tanks down completely).

Quote:
Originally Posted by cadillackid View Post
gnome,

some busses, generally Rear engine busses with non electronic engines had a throttle that was activated by air pressure.. the way it worked is at the pedal you have an air valve that sends air pressure back to a spring loaded actuator.. the mnore air pressure, the more that actuator essentially activated what would have been the throttle cable. if the bus air brake system pressure was not up then the throttle would fail to operate. there should not be an air throttle on a front engine bus..

Christopher
Are you saying the intake tube was restricted ("throttled") like a gasoline motor has a butterfly-throttle-vavle, or are you saying the fuel injector controls were remotely air-operated? I believe the latter...otherwise why would a rear-engine need to be throttled, but not a front-engine? I totally see a remote pneumatic system for the rear makes sense....


Quote:
Originally Posted by cadillackid View Post
being electronic this one should be an electronic fly-by-wire.. make sure the wiring connector at your throttle pedal is plugged in securely and that none of the wires have been damaged or cut.. these wires should feed into a harness going to the Engine computer.. be sure the engine computer connectors are secure as well..
Christopher
Yea, what he said....
Mountain Gnome is offline   Reply With Quote
Old 10-17-2018, 09:16 PM   #14
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,125
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Quote:
Originally Posted by Mountain Gnome View Post
What year is your bus? My 1999 TC1000 5.9L 24V will respond to the accelerator pedal with no air in the system (after bleeding the tanks down completely).



Are you saying the intake tube was restricted ("throttled") like a gasoline motor has a butterfly-throttle-vavle, or are you saying the fuel injector controls were remotely air-operated? I believe the latter...otherwise why would a rear-engine need to be throttled, but not a front-engine? I totally see a remote pneumatic system for the rear makes sense....



Yea, what he said....

Gnome - yes air actuated throttle for the fuel pump.. the air tube is unrestricted at all times.. as you say all of a diesel's throttle control is fuel. on RE busses the distance front to back made mewchanical lionkage extremely sloppy and prone to sticking.. so using air elminated this.. the pump was the same.. but the lever which a normnal throttle cable would push / pull. was activated by an air cylinder.. the pressure in that cylinder controlled by the driver'throttle pedal up front..



-Christopher
cadillackid is offline   Reply With Quote
Old 10-18-2018, 08:29 AM   #15
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
Quote:
Originally Posted by Brad_SwiftFur View Post
Air systems are not terribly complex ... though they can seem to be. You have:


1. Air compressor (and it's related governor, belt/gears, pulleys, etc.) The function of this is fairly straightforward. The governor's job is basically to turn the thing on/off, typically at 90/120 PSI, respectively.
2. Air dryer (on most systems, a few may not have this). The air from the compressor goes through this. Many have "cartridges" or filters that should be changed about once a year (and rarely are). The most common symptom of a failed air dryer is a failure to build up pressure (and usually accompanied by a very noticeable hissing of air from the dryer). Some designs are proprietary to the vehicle to which it's attached, but so-called universal fit designs work just fine in their place.
3. Air tanks. You'll have at least 1 "wet tank", fed by the air compressor, and at least 2 "dry tanks". Sometimes you'll have 1 tank with 2 compartments, or any combination the builder installed. There is often a "protection valve" which will feed the dry tanks once the wet tank reaches a certain pressure. If a tank looses pressure suddenly, this protection valve maintains pressure in the other system, giving you a chance to stop safely.
4. "Everything else". Air brakes, air-ride suspension, parking brakes (also called spring brakes), air-ride seat, gauges, warning lights and buzzers, brake-pressure sensor (the one that makes your brake lights work), and, you guessed it, everything else. The vast majority of this stuff is past a protection valve, basically meaning none of it will work until the system reaches the protection pressure, typically 60-80 PSI. An air-throttle (if you have one) will be on this circuit. Usually the only thing *NOT* on this circuit is the brake pedal, parking brakes, and gauges/warnings. The brakes *NEED* to work at all times, regardless of how much air is in the system.
Thanks for the explanation.

Let me see if I understand how its plumbed correctly. From the compressor to the governor to the wet tank. From the wet tank to the drier and from the drier to the front and rear "dry" tanks. Is that correct? I thought I saw a hose going directly from the governor to the drier but may be I imagined it. I'll check again.

Haven't taken a reading of the wet tank yet. Will do soonest possible.



Quote:
Originally Posted by Booyah45828 View Post

As far as air pressure and throttle issues, as said by others, the throttle is electronic and is completely seperate from the air system. I doubt the two problems are related.
Quote:
Originally Posted by Mountain Gnome View Post
What year is your bus? My 1999 TC1000 5.9L 24V will respond to the accelerator pedal with no air in the system (after bleeding the tanks down completely).
It's a 2002.
Are you missing an "AIR THROTTLE & SUSPENSION" petcock/valve on the manifold by the front air tanks like this one?
Attached Images
File Type: jpg IMG_0966 (1).jpg (258.9 KB, 10 views)
Tomas is offline   Reply With Quote
Old 10-18-2018, 09:02 AM   #16
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,246
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
Quote:
Originally Posted by Tomas View Post

Let me see if I understand how its plumbed correctly. From the compressor to the governor to the wet tank. From the wet tank to the drier and from the drier to the front and rear "dry" tanks. Is that correct? I thought I saw a hose going directly from the governor to the drier but may be I imagined it. I'll check again.

Haven't taken a reading of the wet tank yet. Will do soonest possible.
No, the compressor build the air pressure, then sends it to the drier(driers are optional, most have them, a few don't). It then travels to the wet tank, which will either have the governor attached to it, or it will send a small reference line to the governor wherever it is mounted. Sometimes it's mounted on a frame rail, sometimes it's mounted on the compressor. After the wet tank, air should travel through a check valve into the primary and secondary air tanks.

The governor is nothing more then a spring loaded shuttle valve. When air pressure(around 125 psi) overpowers the spring, the valve moves sending air pressure to the compressor and air drier, shutting the compressor off and purging the drier. When air pressure to the governor drops below 100 psi, the shuttle valve closes, releasing the psi sent to the compressor and drier, allowing both of those items to work again.
Booyah45828 is offline   Reply With Quote
Old 10-18-2018, 11:48 AM   #17
Bus Nut
 
Mountain Gnome's Avatar
 
Join Date: Oct 2017
Posts: 382
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
Quote:
Originally Posted by Tomas View Post
It's a 2002.
Are you missing an "AIR THROTTLE & SUSPENSION" petcock/valve on the manifold by the front air tanks like this one?
I do not have that valve. So you have air suspension!?!?! Lucky....or is that for another air-powered accessory? My air-ride-driver's-seat doesn't work. I wonder which system it takes air from?

Note one valve has been replaced. I need to replace another, but it won't budge to unscrew it. It is my slow leak, especially when cold outside...
Attached Images
File Type: jpg 1018181138[1].jpg (116.4 KB, 5 views)
File Type: jpg 1018181139[1].jpg (149.8 KB, 5 views)
Mountain Gnome is offline   Reply With Quote
Old 10-19-2018, 07:10 AM   #18
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
Yes. Leaf springs in the front and air bags in the back.
Attached Images
File Type: jpg IMG_0889 (1).jpg (160.6 KB, 8 views)
Tomas is offline   Reply With Quote
Old 10-19-2018, 07:22 AM   #19
Mini-Skoolie
 
Tomas's Avatar
 
Join Date: Aug 2018
Posts: 29
Year: 2002
Coachwork: Bluebird
Chassis: TC1000
Engine: 5.9 Cummins 24V
Yes. Leaf springs in the front and air bags in the back.
Tomas is offline   Reply With Quote
Old 10-19-2018, 08:58 AM   #20
Bus Nut
 
Mountain Gnome's Avatar
 
Join Date: Oct 2017
Posts: 382
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
It struck me yesterday that maybe you have a blown fuse. There is a hidden fuse panel on the front-side of the dash-display, behind a screw-on cover with 4 screws on my bus. But none seem related to your issue.
Attached Images
File Type: jpg fuse panel.jpg (216.0 KB, 10 views)
Mountain Gnome is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 03:20 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×