i let my friend use my tb while my motor was in the shop and he was messing with that idle adjustment screw. and now my car dosent idle right and it get a tps code saying throttle position wrong. does anyone know how i can get that screw in the right place? for that code i think i can fix that by adjusting the tps

 

you have to play with it and get it above 4.3 at wot or it will throw code get a volt meter and tap into the wire and hold it at wot and see what voltage its reading...the best way to adjust it is drill the screw holes bigger in the tps and adjust till you get the right voltage...

 

so what does the idle screw do? does it mess anything up if its messed with.

 

It's the throttle stop screw. If adjusted too much one way or the other, the IAC may not be able to control the idle.

 

Back the screw out slowly until the engine is running at the programmed idle speed. Use a scanner to get the exact RPM off the PCM, not the tach. When the idle is correct, check the IAC "counts". Hopefully they will be in the range of 20-40 counts. If they are too low, back the stop screw out a little more. If they are too high, screw it back in slightly.

When you've got the idle speed correct and the IAC counts correct, check the CLOSED THROTTLE TPS voltage (not the WOT voltage). It should be between 0.20-0.80Volts. Some people will slot the holes and adjust it to 0.50-0.65V. As long as its under 0.9V the PCM will baseline that as the 0% throttle position, then prorate up by adding 4.0V to get an aprrox WOT reading. You can check to see that the WOT reading is about 4.0V above the closed reading, but its not critical. The PCM will not set a code unless it goes over 4.90V.