Viable Option for TPS Replacement

[Tom]

I have no idea if this is the case, but if there is one that differs only in the potentiometer value, then we can come up with a custom KLR chip image that's calibrated appropriately. It would still need to have a compatible idle switch of course.

So Johnb, for a potential substitute TPS, must the needed values of the potentiometer and idle switch be determined only by testing them or is there manufacturers technical data/specs available of the components which can be used?

The specs are published in the manual. From our CP test guide linked below: To test the TPS potentiometer in the car, pull the connector off the KLR and test the resistance between Pins 22 and 23. The reading should be 320 to 670 ohms with your foot completely off the gas pedal, and should increase to 2.7k to 4.7k ohms as you slowly press the gas pedal to the floor. The reading should increase smoothly and steadily, without breaks or erratic readings.

https://www.carpokes.com/viewtopic.php?t=525

[breilly951]

I have no idea if this is the case, but if there is one that differs only in the potentiometer value, then we can come up with a custom KLR chip image that's calibrated appropriately. It would still need to have a compatible idle switch of course.

So Johnb, for a potential substitute TPS, must the needed values of the potentiometer and idle switch be determined only by testing them or is there manufacturers technical data/specs available of the components which can be used?

The specs are published in the manual. From our CP test guide linked below: To test the TPS potentiometer in the car, pull the connector off the KLR and test the resistance between Pins 22 and 23. The reading should be 320 to 670 ohms with your foot completely off the gas pedal, and should increase to 2.7k to 4.7k ohms as you slowly press the gas pedal to the floor. The reading should increase smoothly and steadily, without breaks or erratic readings.

https://www.carpokes.com/viewtopic.php?t=525

Thanks Tom, but I guess my question wasn't clear. What I was trying to ask was if there are available manufacturer published specifications for all the Bosch TPS so you could review and compare the resistance/values of the "potential replacement" to the original TPS value ranges for compatibility or is purchasing and testing the only way to determine if it will work.

[Tom]

So Johnb, for a potential substitute TPS, must the needed values of the potentiometer and idle switch be determined only by testing them or is there manufacturers technical data/specs available of the components which can be used?

The specs are published in the manual. From our CP test guide linked below: To test the TPS potentiometer in the car, pull the connector off the KLR and test the resistance between Pins 22 and 23. The reading should be 320 to 670 ohms with your foot completely off the gas pedal, and should increase to 2.7k to 4.7k ohms as you slowly press the gas pedal to the floor. The reading should increase smoothly and steadily, without breaks or erratic readings.

https://www.carpokes.com/viewtopic.php?t=525

Thanks Tom, but I guess my question wasn't clear. What I was trying to ask was if there are available manufacturer published specifications for all the Bosch TPS so you could review and compare the resistance/values of the "potential replacement" to the original TPS value ranges for compatibility or is purchasing and testing the only way to determine if it will work.

Ah, I dunno

[breilly951]

The specs are published in the manual. From our CP test guide linked below: To test the TPS potentiometer in the car, pull the connector off the KLR and test the resistance between Pins 22 and 23. The reading should be 320 to 670 ohms with your foot completely off the gas pedal, and should increase to 2.7k to 4.7k ohms as you slowly press the gas pedal to the floor. The reading should increase smoothly and steadily, without breaks or erratic readings.

https://www.carpokes.com/viewtopic.php?t=525

Thanks Tom, but I guess my question wasn't clear. What I was trying to ask was if there are available manufacturer published specifications for all the Bosch TPS so you could review and compare the resistance/values of the "potential replacement" to the original TPS value ranges for compatibility or is purchasing and testing the only way to determine if it will work.

Ah, I dunno

I tried to see if I could find them on the Bosch site and other sources to no avail. But honestly, not sure they would have provided me any clear-cut answers anyway. Guess it will be biting the bullet for an OEM - ouch! thanks

[t36]

Thanks Tom, but I guess my question wasn't clear. What I was trying to ask was if there are available manufacturer published specifications for all the Bosch TPS so you could review and compare the resistance/values of the "potential replacement" to the original TPS value ranges for compatibility or is purchasing and testing the only way to determine if it will work.

Ah, I dunno

I tried to see if I could find them on the Bosch site and other sources to no avail. But honestly, not sure they would have provided me any clear-cut answers anyway. Guess it will be biting the bullet for an OEM - ouch! thanks

there is a chap on Ebay who reconditions these units.
https://www.ebay.com/itm/197603630834
here is a link. For future google searchers who end up this page. The sellers name is nla944parts.

[mikey_garcia]

Ah, I dunno

I tried to see if I could find them on the Bosch site and other sources to no avail. But honestly, not sure they would have provided me any clear-cut answers anyway. Guess it will be biting the bullet for an OEM - ouch! thanks

there is a chap on Ebay who reconditions these units.
https://www.ebay.com/itm/197603630834
here is a link. For future google searchers who end up this page. The sellers name is nla944parts.

My idle switch broke so I bought a refurbished one from that seller and was disappointed with the quality of it...

The switch wasn't even sealed. The lid didn't pop on all the way cause the sealing surface was so marred. The idle switch was barely glued down, it was mostly the solder that was holding it down. It wasn't the stock idle switch, just another switch from something else.

For the price he was charging($360) it was a bit annoying. Looks like he doesn't have any full sensors for sale anymore, just refurbishes the ones you send him for $155

Ended up snagging an NA tps and using the idle switch from that to fix mine. The NA switch is a lot bigger and required a bunch of sanding of the plastic body and leads until it was perfect. The NA switch seems a lot more durable.

[t36]

I tried to see if I could find them on the Bosch site and other sources to no avail. But honestly, not sure they would have provided me any clear-cut answers anyway. Guess it will be biting the bullet for an OEM - ouch! thanks

there is a chap on Ebay who reconditions these units.
https://www.ebay.com/itm/197603630834
here is a link. For future google searchers who end up this page. The sellers name is nla944parts.

My idle switch broke so I bought a refurbished one from that seller and was disappointed with the quality of it...

The switch wasn't even sealed. The lid didn't pop on all the way cause the sealing surface was so marred. The idle switch was barely glued down, it was mostly the solder that was holding it down. It wasn't the stock idle switch, just another switch from something else.

For the price he was charging($360) it was a bit annoying. Looks like he doesn't have any full sensors for sale anymore, just refurbishes the ones you send him for $155

Ended up snagging an NA tps and using the idle switch from that to fix mine. The NA switch is a lot bigger and required a bunch of sanding of the plastic body and leads until it was perfect. The NA switch seems a lot more durable.

Oh wow!! That’s disappointing to hear. I’m glad you figured out a fix. We just gotta figure out what micro switch would be available new and swap in

[breilly951]

there is a chap on Ebay who reconditions these units.
https://www.ebay.com/itm/197603630834
here is a link. For future google searchers who end up this page. The sellers name is nla944parts.

My idle switch broke so I bought a refurbished one from that seller and was disappointed with the quality of it...

The switch wasn't even sealed. The lid didn't pop on all the way cause the sealing surface was so marred. The idle switch was barely glued down, it was mostly the solder that was holding it down. It wasn't the stock idle switch, just another switch from something else.

For the price he was charging($360) it was a bit annoying. Looks like he doesn't have any full sensors for sale anymore, just refurbishes the ones you send him for $155

Ended up snagging an NA tps and using the idle switch from that to fix mine. The NA switch is a lot bigger and required a bunch of sanding of the plastic body and leads until it was perfect. The NA switch seems a lot more durable.

Oh wow!! That’s disappointing to hear. I’m glad you figured out a fix. We just gotta figure out what micro switch would be available new and swap in

t36 thanks for the ebay info. I checked it out and figured it might be worth the effort but Mikey_Garcia your posts kind of brings me back to square one.

In researching last night, I saw where 944 Online is selling the 0 280 120 431 TPS for Audis (out of stock) as a replacement for the 951s, so maybe it will be OK. Interested if anyone has installed this one and how it has performed?

[MoeMonney]

My idle switch broke so I bought a refurbished one from that seller and was disappointed with the quality of it...

The switch wasn't even sealed. The lid didn't pop on all the way cause the sealing surface was so marred. The idle switch was barely glued down, it was mostly the solder that was holding it down. It wasn't the stock idle switch, just another switch from something else.

For the price he was charging($360) it was a bit annoying. Looks like he doesn't have any full sensors for sale anymore, just refurbishes the ones you send him for $155

Ended up snagging an NA tps and using the idle switch from that to fix mine. The NA switch is a lot bigger and required a bunch of sanding of the plastic body and leads until it was perfect. The NA switch seems a lot more durable.

Oh wow!! That’s disappointing to hear. I’m glad you figured out a fix. We just gotta figure out what micro switch would be available new and swap in

t36 thanks for the ebay info. I checked it out and figured it might be worth the effort but Mikey_Garcia your posts kind of brings me back to square one.

In researching last night, I saw where 944 Online is selling the 0 280 120 431 TPS for Audis (out of stock) as a replacement for the 951s, so maybe it will be OK. Interested if anyone has installed this one and how it has performed?

not bad for about $50 shipped.
https://www.ebay.com/itm/205856546583?_ ... R5DwuaOAZw

[walfreyydo]

Youd have to do some more digging on this but I believe the BMW M50 TPS (variable TPS like the 951) *may* fit the 944 throttle body with an M20/M30 TPS adapter plate. The M20/M30 TPS sensors were from BMWs from around the same time period as the 944, primarily the E30

These are commonly used to run standalone EMS on older bmw's which require a variable TPS. I was looking at this as an option to convert my S2 to Megasquirt, but instead opted for a 968 TPS, which is also variable and *may* also be another option. I never fully investigated whether the adapter plate will work on a 944 throttle body, but at first glance it seemed like it might.

Couple examples of the adapter plate:
https://falkmfg.com/products/m50-tps-ad ... -1fqZKk4YL
https://angry-ass.com/product-organizer ... dapter-m20