Skip to main content ↑ ↓
Topic: Throttle Position Sensor & Air Throttle (Read 891 times) previous topic - next topic

Throttle Position Sensor & Air Throttle

I am making progress on my air throttle project with the end goal of eliminating the King unit. I've got the air hose run, pedal (treadle) installed, throttle control cylinder installed and the TPS (throttle position sensor) installed BUT I can't find the Allison TPS wires & plug. Anyone know where they are?

I'm looking in the bundle at the transmission and in the bundle in the engine compartment that feeds the King unit. I found a plug near the King that fits the TPS but the wire numbers indicate they are for "Throttle Cruise." I found another one but it has only two wires. Anyhow, does anyone happen to know where I can find this elusive plug? Thanks.
jor

93 225
95 300
97 270
99 320

Re: Throttle Position Sensor & Air Throttle

Reply #1 –
John,

I'll get out in the morning and look at our TPS.  Will try to see where the signal output wire goes.  Too hot to look right now - 95 in the shade and going to 100 every day this week.  I think summer has really arrived in West TX.


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Throttle Position Sensor & Air Throttle

Reply #2 –
Jor:
Not for sure this is what you are looking for.
Steve at King Control, told me the TPS data is fed from the King Control Unit and the attached drawing is mis-labeled, the arrow is pointing to a FILTER and not a TPS Sender. Steve said the system works without the filter. So I assume this plug is sending the TPS data to the Allison, hope this helps. Following your progress, best of luck in the conversion.
Regards,
Charles
W5CRY
1997 Dynasty - Sold

Re: Throttle Position Sensor & Air Throttle

Reply #3 –
I hope someone makes a detailed you tube video of the procedure.

Re: Throttle Position Sensor & Air Throttle

Reply #4 –
Another vote for a real detailed write up and video. Many of us will be in your debt.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: Throttle Position Sensor & Air Throttle

Reply #5 –
Quote
real detailed write up and video

I'll post a good write-up when I get done. I'm making progress slowly. As far as I know only one other member has done the conversion himself and I have a PM into him. I went by the schematic that cry42 posted (thanks) and I found the connector from the King for the King TPS. The wire colors on the King unit are consistent with that schematic.

The wires on the chassis side, however, are of different colors than on that schematic. There are three wires in what appears to be a factory tape wrap and a 4th that may have been added. The three wires are numbered. The numbers are 124, 156 and 203. The extra is not numbered and I suspect it must have been used in the King installation. Anyhow, I checked an Allison schematic and i see the three TPS wires coming from the transmission. They are numbered 124, 156 and 135. That "135" was disappointing.

I'm going to check the origin of those wires at the transmission and see if the numbering is consistent. Anyhow, slowly but surely.
jor

93 225
95 300
97 270
99 320

Re: Throttle Position Sensor & Air Throttle

Reply #6 –
John,

Here's the photos of the transmission TPS on our coach.  Not great, but best I could do.

The wires coming out of the TPS are red, blue and green.  They disappear into a slit wiring loom.  Where they go after that - no idea.

Tried to get a shot of the TPS/throttle cable bracket.  Also not great photos.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Throttle Position Sensor & Air Throttle

Reply #7 –
Quote
Here's the photos of the transmission TPS on our coach.

Chuck, these photos are helpful. Thanks. I have the same three colors and am going to trace back to the transmission to make sure they are consistent as the number on my green wire differs from that on the Allison schematic. Also, I am interested in the linkage at the engine. Thanks.
jor
93 225
95 300
97 270
99 320

Re: Throttle Position Sensor & Air Throttle

Reply #8 –
The TPS linkage is hard to photograph - can't get my phone down there at a good position.

The TPS cable end is a flat metal piece with a slot in it.  The slot fits over a post on the engine fuel control lever.  When the fuel control lever is moved by the throttle cable, the post moves until it reaches the end of the slot, then the TPS cable moves.  I found another post with a better photo of the TPS linkage:

King Cruise Closed - suggested replacement?

The apparent aim of this setup is to allow a certain amount of movement in the fuel control lever before the TPS receives any input.  Document below shows how to adjust the TPS.


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"