thottle position sensor

[nc89sho]

ok, i accidentally started the car today without the TPS plugged in. and i noticed that it actually ran better. and the "just off idle" was more responsive. of course if i goosed it it would die, but just giveing it a little throttle the engine picked up alot faster. i plugged the TPS back in and the partial throttle "just off idle" problem came back.. this is a pretty new TPS. could it be adjusted wrong? or just defective? or is that normal. any advice will help. thanks in advance..

 

[sdpatt]

Yes it could be adjusted wrong. It should be adjusted to output under 1.0V at idle. There is a tiny amount of adjustability available with the two mounting screws. I believe there was a topic on this board that discussed which terminals to test for the output voltage.

Did you ever reset the programming after installing the new TPS? That must be done.

 

[nc89sho]

yes, i reset the computer many times since then. do the simptoms i described sound like a bad/out of adjustment TPS. or is that normal.

 

[rangerj]

nc89SHO,

The throtle position sensor (TPS) connector is rectangular in shape. At one end will be a "leg". The leg would make it look like an "L" if you "stand it up". The first wire at the end with the "leg" is the voltage refference (VREF).

Moving up the connector the middle wire is TP signal wire (TP sig), and the third wire is the signal return wire (sig rtn).

VREF test---With the KOEO (key off for at least 10 seconds if you were running) disconnect the TPS connector. With a volt meter probe between VREF and SIG RTN at the TPS harness (not the sensor). You should get between 4 and 6 volts. If not, check VREF circuitry and wiring.


TP signal----KOEO Backprobe TPS connector between TPS and SIG RTN, Move the throttle between the entire range, i.e. fully closed to wide open. Do this slowly and watch for any breaks.

The voltage should range (increasing as you open the throttle) from 0 to 5 volts with out any breaks as the throttle is moved through the range. If any breaks, or to little , or to much voltage, the TPS is faulty.

NOTE. as the throttle is never at 0 (zero) percent, ie 100 percent closed, voltage should start out at about 0.5 to 0.6 volts. (I have seen them as low as 0.33) The target is 0.6 to 4.5 volts as the range. As Scott said you can ever so slightly "adjust" the TPS to get 0.6 volts as the closed throttle starting voltage.

Scott,

If it had a pushrod it would work much better!
Tongue planted firmly in cheek. Chuckle, chuckle! thumbs_u (nc89 this is a private joke, pay it no mind)

Hope this helps, rangerj