Hey, I asked this at the TPI board, but nobody answered on it yet, and I'm going to the track tomorrow, so..

If it's impossible to get the 4.60 "WOT" voltage out of the TPS through adjusting it, does that mean the TPS is bad? Right now I can just get 4.28 volts out of it; tonight I'm unhooking the TV cable to try it again. If I can't get past 4.28 @ WOT, does that mean it's a bad TPS? I have a few spares in the basement


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
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Tom,

According to my data, the ECM considers anything above 80% as WOT conditions and will go to Open Loop mode. That means that you really need to get to 80% of the difference of 5.0 VDC minus the vlotage at idle postiion (ideally 0.54 VDC), or 3.57 VDC. Even if you presume 0 VDC as the base line, 80% would only be 4.0 VDC. No problem.

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Later,
Vader
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"Make Me Bad"
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Vader speaks the truth. I have confirmed this with my Diacom scan tool.

 

Hey Tom, do you have to unhook the TV cable while adjusting the TPS ? ( Just wondering because I'm gonna do mine this weekend )

 

Great! Thanks, Vader & Glenn.

Why the heck do we adjust a TPS by voltage? Why can't we just measure the resistance of the sensor directly, independent of the car/computer wiring?

Voltran, that was a suggestion from someone on the TPI board. I hadn't heard it before, so I gave it a shot- and determined that it's not necessary. Before I played with the TPS screws, I took a reading of WOT with the TV cable hooked, and another one with the cable unhooked. There were no differences in the voltage, either way.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!