Air Throttle and Cruise Control

Jcparmley · November 20, 2018, 03:44:51 PM

I have been looking on the forum for an answer to this question but I haven't been able to find it. I have a 89 MCI 102c3 6v92TA MUI (non DDEC). I currently have cruise control. If I add a air throttle would I still retain my cruise control?

buswarrior · November 20, 2018, 03:56:44 PM

Which system do you have, and on what throttle parts does it act on?

You'll probably be fine, so long as the air throttle is properly installed and well modulated.

happy coaching!
buswarrior

Jcparmley · November 20, 2018, 07:54:12 PM

I have not purchased the air throttle yet. I was just considering using one. I do not have a DDEC bus, so I do not have a electronic throttle. I have the OEM throttle that seems heavy. My plan is to lube the cable when I open the floor up. But I was considering an air throttle, which people seem to like.

Quote from: buswarrior on November 20, 2018, 03:56:44 PM
Which system do you have, and on what throttle parts does it act on?

You'll probably be fine, so long as the air throttle is properly installed and well modulated.

happy coaching!
buswarrior

buswarrior · November 20, 2018, 08:37:52 PM

No, what cruise control system do you have?

happy coaching!
buswarrior

Bill Gerrie · November 20, 2018, 09:06:41 PM

I had a cruise control on a non DDEC bus and the cylinder pulled on the throttle pedal because the accelerator on top of the governor is way too stiff for the unit to pull it. It worked very well. I now run a DDEC unit and the computer controls the cruise control function.

richard5933 · November 21, 2018, 06:16:54 AM

Quote from: Jcparmley on November 20, 2018, 07:54:12 PM
...My plan is to lube the cable when I open the floor up...

Not sure if the MCI is anything like the GM, but couldn't you lubricate the throttle cable without opening the floor? On the GM you can pull the cable easily from the rear end by disconnecting the clamps on both ends. Remove the cable, clean it thoroughly, lubricate, and then reinstall.

I've read about many who have had success pulling, cleaning, lubricating the cable this way. Hopefully others will confirm if this will work on the bus you have.

One word of caution though, when I tried that on my GM 4106 I discovered the hard way damage to the tube carrying the cable. When I attempted to reinstall the cable it wouldn't go back in, and I had to repair a small section of the tube which had worn through. The worn spot had collapsed and was causing the heavy throttle, not lack of lubrication.

luvrbus · November 21, 2018, 06:49:18 AM

MCI uses a Morse cable sealed inside a housing most the time not much you can do but replace it when it goes bad,he probably has a sharp bend some where causing his problem,some you can remove the cable on a Morse but most you cannot remove the cable from the housing

Jcparmley · November 21, 2018, 01:27:26 PM

I'm not sure. I assumed it was OEM and came with the bus.

Quote from: buswarrior on November 20, 2018, 08:37:52 PM
No, what cruise control system do you have?

happy coaching!
buswarrior

TomC · November 23, 2018, 10:13:26 PM

The big question is how the throttle modulator works. If it is cable driven off the governor, then you can mount the cruise control on the governor and mount the air throttle on the governor in the engine compartment. But most air throttles (like mine) have an air operated throttle modulator on the Allison transmission. Hence you cannot run the cruise control off the governor of the engine since the throttle modulator would not be getting any air pressure to operate properly. I run my King Cruise off my gas pedal. It pulls down on the air throttle in the driver's compartment, thus keeping the air modulator working properly in proportion to the throttle. Good luck, TomC

chessie4905 · November 24, 2018, 11:40:30 AM

That is how I have mine hooked up. That way the control box stays clean and dry in the compartment under driver and not a lot of wire to run. Speed sensor pickup comes off speedo head.

kyle4501 · November 25, 2018, 06:10:21 PM

What happens when the king cruise is attached directly to the governor with an air throttle?

Mine seems to work fine. What am I missing?

chessie4905 · November 26, 2018, 05:28:21 AM

They will work either way fine. If you are starting from scratch, a Rostra cruise control will work on air throttle best up front off pedal and is much cheaper than a King cruise. Used to be a guy on BNO that sold them and provided lots of help in installations and settings.

uncle ned · November 26, 2018, 08:11:34 AM

Kyle

Hope you had a nice thanksgiving.

King cruse controls work fine off the governor. But on the roads I travel I can never find a place to use it.

uncle ned

kyle4501 · November 29, 2018, 06:19:53 PM

Quote from: uncle ned on November 26, 2018, 08:11:34 AM
Kyle

Hope you had a nice thanksgiving.

King cruse controls work fine off the governor. But on the roads I travel I can never find a place to use it.

uncle ned

I need cruise control to keep my speed in line with the posted limits . . . . otherwise I'll be at 80 mph!

Bill Gerrie · November 30, 2018, 06:48:35 AM

I think the guy you are referring to for the Rostra cruise control was Pete Papas in FL. I don't know if he still does as he sold his RTS a long time ago.