tps won't read 0
 

i have a ls based motor swapped in a lt1 firebird, still using the lt1 cluster. running a stock 99 pcm, tuning with efi live, i can't get the tps to read 0 so i can get into the idle tuning correction pids. i've tried 2 sensors so far, same result, most of the time, after doing the following for resetting the tps, i get the same value i started with.

Engine off
Pull out TPS connector
Turn on ignition
Wait till SES light
Turn ignition off
Plug back in TPS connector

the throttle body is a edelbrock 90mm if that helps at all.

do i have to have the engine warm when i do this? currently doing it while its cold (sat overnight)

Maybe you want to slot out the TPS holes and get
it to read a proper voltage at closed position (and
be sure that doesn't then limit your WOT voltage).

I had to slot the holes on my tps on my Holley TB. Is your adjustment screw set right?

what do you guys mean slot the hole, my tps sensor has been tripping out to since I put a fast 90/90 on my car..

The holes in the TPS for the mounting screws. Take a file and oval them so that you can adjust the sensor.

After resetting TPS;
0% = 0.6v
100% = 4.7v
TPS voltage CAN NOT BE MORE THAN 4.7v for 100%

well right now i'm reading
0%=0.8V
100%=4.5V

hopefully this is ok.

how the heck do you adjust it? do you put a mutimeter on it and see what it reads? my car keeps throwing a code for the tps sensor but i've changed the sensor a numerous amount of times, even broke one cause it was pissing me off

i did it thru efi live and the throttle stop screw. i have an edelbrock tb on my car.

When you slot the holes you may also need to remove the locator pin on the sensor. Just file or cut it off. The spec is .45 - .55 volts and 0% throttle angle (obviously a scan tool is needed) at idle. Anything higher will put the PCM fueling into a different mapping cell in the tables and it will think it is no longer in idle mode.

Maximum voltage is 5.0 volts, not 4.5v.

If you are having idle issue, the IAC and TPS may both need work. Here is a good procedure that works.

If you are having idle issues you may need to reset your Idle Air Control (IAC) and TPS, do this before you start drilling holes in your throttle body (TB) blade. I have used this procedure on some huge cammed cars and it worked.

1) Monitor your IAC, Idle Speed, throttle position voltage and your throttle position %.
2) With the key in the ON position, adjust your TB set screw until your throttle position is 2%.
3) Turn your key to the OFF position.
4) Unplug your Throttle Position Sensor (TPS) and IAC.
5) Turn your key to the ON position for a few seconds, and then OFF again.
6) Plug in the TPS and IAC and then turn your key to the ON position and restart logging. Your throttle position will now be reset to 0 degrees and about .45-.55 volts.
7) Start your engine, your IAC should be 40-60 for a cammed engine.

If you are not at your desired IAC position, redo the above procedures in smaller increments.

After resetting the TPS and you see above 0% and 0.6V
you probably have something going on in the tune that is commanding
higher TPS%.

A mechanical linkage throttle body will not be commanded to any position by the PCM because it has zero control of it, your foot does.