Different Tps Question

rkutzner

Founding Member
Jun 20, 2002
57
0
6
Westminster, MD
OK, I've researched this to death but still have a question. On 03 Mach1 everything keeps showing DY967 as my TPS. But with what looks like 2 brass lined holes I just don't see how it can be adjusted on a stock throttle body. I can't believe in this day and age the ECM doesn't baseline this reading at startup. Even my 08 Buell 1125R does that! What am I missing ? I'm old to cars, but new to this 03! And loving it. IMG_20170714_164322624_BURST000_COVER.jpg
 
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OK, I've researched this to death but still have a question. On 03 Mach1 everything keeps showing DY967 as my TPS. But with what looks like 2 brass lined holes I just don't see how it can be adjusted on a stock throttle body. I can't believe in this day and age the ECM doesn't baseline this reading at startup. Even my 08 Buell 1125R does that! What am I missing ? I'm old to cars, but new to this 03! And loving it.
+1 on above. There isn't a need to "adjust" the TPS on the 1996+ model year. The PCM notes the TPS value at each start up and then calls that value the "closed throttle" value. When the PCM "sees" that same value (or lower), it calls the throttle state as closed. If the TPS value is greater than the initial stored value then the PCM calls the throttle mode a "part throttle". There's some maximum value (something slightly less than 5 volts) that the PCM will call the throttle state as wide open throttle (WOT).

It's important to note that the PCM does not care about the amount that the throttle is open. Only 3 states matter. This is very different from the Speed density days where the TPS value indicated about how much throttle that the driver was requesting.

It's the PCM's ability to remember the initial TPS value that makes adjustment of the TPS no longer needed. However for proper idle control it's vital for the TPS to send the SAME value EACH time the throttle is closed.

Does this help?
 
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Thanks guys, it is all stock so since my obdii relative reading is very jumpy, especially at the bottom, when going through the pedal range I'm gonna replace it and go from there! I have a slight hesitation under load at the very bottom of the gas pedal, mostly when cruising with the foot barely on the gas. Car has 100K and sat for 18 months so have to run some fresh feul and cleaner through a few tanks before pursuing any further!
 
UPDATE. Those Bluetooth OBDII dongle thingys are pretty amazing for $12 and the $5 Torque phone app. My TPS would jump from it's initial relative 20% to 35% after pushing the pedal down slowly....dead spot. Then it would go up smoothly to ~92%. $32 later and the new TPS moves consistent with the pedal, same 20-92ish. From what I've read, that's about right. Problem solved, Mach running like a bat outta.....my cramped garage !