8.3 Cummins Mechanical Throttle Position Sensor

[deandec]

Where should I look for this component?

Anyone have a photo of what it looks like?

Or, do I even have one?

TIA for any help.

[Bob_C]

Google your question for a quick response...forum has been a little slow....

[deandec]

Originally Posted by bob caldwell

Google your question for a quick response...forum has been a little slow....

I have a lot of Google search experience.

No answer has been found with my efforts.

[Bob_C]

I know smaller engines do.....found them advertised in a catalog....

[Ray,IN]

Most drive-by-wire diesels have the TPS on the accelerator pedal. If yours is cable-controlled it should be on the injector pump.

[deandec]

Thanks for the drive by wire answer. Perhaps similar to my Air Throttle?

[deandec]

Thanks for the drive by wire answer. Perhaps similar to my Air Throttle?

Here is a photo of the linkage portion of the fuel system.

[deandec]

Well, I took a longer look at my old Gillig Parts Manual. It has detailed exhibits for the Air Throttle & Cruise Control System as well as the Transmission Shifting System.

On the Transmission is a bracket that holds the Throttle Position Sensor.

It appears to connect to the rubber billows type TPS link in the picture below.



I have had some shifting problems that I suspect are due to the TPS function.

Perhaps that collapsed rubber billows in the picture has to be positioned in a straight line like the exhibit shows and not as it currently positioned..

Will post back when I have corrected the positioning and test driven the rig.

[deandec]

I disconnected the throttle linkage to which the TPS billows link is attached (pictured in my prior post).

After cleaning and lubing all the sliding parts and reconnecting them, I now have a sprightly shifting experience from 1st to 5th gear. (never got to 60 mph and 6th gear)

The billows also sits more straight line than it did before disassembly.

No guarantee this is the final "fix" but I am pleasantly encouraged.....

This is a two year issue that may have started with the throttle linkage becoming disconnected while crossing the San Mateo Bridge in SFO area.

Because my throttle is an "Air Throttle" it may be different from other Cummins linkage of the same vintage.

[RKins]

I guess I'm confused Dean. Both pictures look the same. Are you saying the TPS connects inside the billows portion?

Also, what do you mean by "Air throttle"? Do you not have a cable running from pedal to throttle?

[deandec]

Originally Posted by RKins

I guess I'm confused Dean. Both pictures look the same. Are you saying the TPS connects inside the billows portion?

Yes, as mentioned in an earlier post, the TPS is in a bracket on the tranmission case.

Its connection to the engine throttle appears to be inside the billows in the picture.

Also, what do you mean by "Air throttle"? Do you not have a cable running from pedal to throttle?

My rig's acceleration is controlled with compressed air at the accelerator pedal.

If the compressed air is not above @ 60psi with the engine running there is no input to the engine throttle from the accelerator pedal in the cab.

I have not identified how it links to the throttle.

This feature can hinder a fast getaway......

Note: this is a Gillig Chassis thing I understand.

[deandec]

Air Throttle

Here is a simple diagram of an Air Throttle for those that might be interested.

[Ray,IN]

Thank you for explaining the air throttle Dean! I have learned something new today. Sorry I didn't get back to you, for some reason I had stopped getting notifications for a while, corrected that in my preferences selections.
It's great you found the problem and the solution.

[RKins]

Yup I learned something new also. I might have to dig deeper into that product.