Re-thinking... I don't think the specs shown above are enough to match the WSM data. The (fixed) total resistance of the potentiometer is 2000 ohms (across pins 1 and 2), but the value across the wiper pins is 850 ohms ~ 2700 ohms (3 & 2). You would have to know the values of the resistors (rectangular boxes) shown in this wiring diagram: Image Unavailable, Please Login
As you can see the intake plenums are missing and therefore any Mass Air sensor. As a result I am not able to use either the Bosch 2.7 or 5.2 ECU. This application uses a PROEFI system.
Bosh manufactures auto parts in China, Germany, the USA, ....... I haven't noticed any quality issues regardless of there they were manufactured. Anyway there are many substitutes. Go to RockAuto and look at 1995 Porsche 911. Uses the same TPS.
If the PROEFI is programmable, would it matter what kind of TPS you had fitted? I guess it would depend on the flexibility of the programming. Using the values given in the WSM, I can't see how the voltage output of the OEM TPS can be linear. Image Unavailable, Please Login The resistance measured across the potentiometer (Rv) may be linear with throttle movement, but the TPS presents a circuit with 4 resistors in it.
Miro posted this TPS interchangeability chart a while ago: Image Unavailable, Please Login So the cheaper, more readily available Bosch 0 280 122 001 sounds like the best option.
I agree but it is the situation as it exists. Bosch was once run by engineers. Imperfect engineers but they enforced their standards. It is now run by the bean counters.
I have seen Bosch TPSs from Latfia and Korea as well. Thanks for the tip on Rock Auto. I have never used them but will check it out.
I use rock auto all the time. I bought 02 sensors from that region once, malfunctioned in 3 months actually was worse than the ones I replaced. Bought them new from rock auto, issues gone. Now I just go there and search for bosch part numbers. FPR, IAC, Fuel pumps, TPS everything.
I have Bosch parts on the shelf from Potugal, Czech Republic, Bulgaria. They are also in Russia, India. Better than the knock offs usually but for sure not what they used to be.
I bought 2 new O2 s for our Mercedes and the CEL came right back. Diagnosed everything. All indicators pointed to bad O2. Bought another. Still a CEL. After a talk with an OEM engineer friend from Dearborn I bought another at the Mercedes dealer and the light has been out for 2 years now. After my next conversation with same friend he said "you really don't thing they are selling you the same quality they are selling us do you?"
I checked Rock Auto under 1995 Porsche 911 and scanned the available choices but none of them cross referenced the Bosch numbers. I selected the one that I felt had the best technical description and have it on order. Is there anything that I should know about the installation? I see that you have to slide the senor onto the throttle shaft orientation but now you have to rotate the sensor body to line up with the mounting holes. Does this sensor body rotation not mess up the reostat position? Thanks
Look under "Part number search" put in the full Bosch number and answer the drop downs. I just tried. Rock Auto does not seem to have it.
???? Do you that the TPS is the problem or are you going with it because of the first you replaced it the problem stop It would suck if after you got a OEM part “paying the F tax” and it didn’t fix the problem I usually get my parts straight from Bosch parts and never had a problem it’s less then “OEM” and little more then parts houses but I feel it should be the same Quality Sent from my iPhone using FerrariChat.com mobile app
I looked up Bosch on the internet and their tech "contact" was a 888 telephone number. I called becauseIwantedtoknowthedifferencebetweenthe001, 004 and the 005. They told me to email [email protected]. I did that and got an auto reply telling me to call the number that told me to email them. Still hope to hear from them.
The website is “Boschautoparts.com” that will bring to the home page enter the year make and model then what you are looking for it will show direct fit parts with data sheets Think I read that 004 has 2 contractors on it and 005 is brand specific and 001 is the base model for the 3 wire sensor and -201 to 205 is a 4 wire sensor I never replace my TPS “yet lol” but have gotten coils fuel pumps and other stuff with no problems I have even got parts for my daughters 2013 c70 and save money over OEM I called the help line once for a different matter then yours and they got what I needed in no time As far as where the parts I have gotten where made it’s all of the world but it does come in a Bosch box and I never had to return anything “yet” so I use them Sent from my iPhone using FerrariChat.com mobile app
These are the resistance values consistent with the WSM. As long as the ECU has a high input impedance (compared to the pot) for terminal 3 and draws insignificant current, the signal voltage at 3 will be linear. Image Unavailable, Please Login
Good math, John! I solved the pot value, but got stuck after that. I don't know whether the range limit of the pot is significant. The whole slider is not used. Perhaps that's where the WSM 20% tolerance comes in. I'll add these values to my wiring diagrams.
I found very minimal movement for adjustment on my 5.2 sensor body (mine was slightly out of tolerance and I couldn't adjust it properly). I haven't noticed any adverse effects. Up to a point, I believe the OEM Motronics ECU adjusts to the sensor output voltage value sensed at idle (pedal not pushed). I can't say what your programmable ECU does.
I don't have a diagnostic sheet for the 2.7 car, but the expected signal voltage at the ECU from the TPS would be: I'm not sure where and how you would measure "72 degrees" I'm also not sure what voltage the ECU is supplying to the TPS (5vdc?)
Image Unavailable, Please Login Image Unavailable, Please Login Data sheet says 5 volts Sent from my iPhone using FerrariChat.com mobile app
Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login The service manual has a detailed way of setting up the TPS and syncing everything up The pics are just some of what is needed but there is more to do and it says that anytime a component to the throttle system is repair or replace you need to readjust it Sent from my iPhone using FerrariChat.com mobile app
