I just put a new throttle position sensor on my 1990 GTA speed density and after i put it on it ran good for a while but then it idled fast then check engine came on and idled slower about normal but was really really rich, is the sensor bad or what and ps the O2 sensor is new, any help would be appreciated.

 

when you put it on did you check the adjustment with a dvom or multimeter. from the factory it is set a .54 volts with the throttle closed and you can go as high as .64 volts with out seeing the check engine light

 

I didn't know you could adjust these and how do you check the voltage and adjust them it worked fine when I put the old sensor back on, well as fine as it was before I replaced the old one because some of the resistors are bad I think in the old one because when it hits a certain throttle point it just cuts out and almost dies then runs fine above or below that throttle position

 

to adjust the tps just loosen the mounting scews and with the throttle valve in the closed idle position and the ignition turned to the on position connect the jumper wires to the top two wires coming off the tps( I back probed them you can also pierce the wires)and just move the tps up or down and the volts should increase and decrease as it moves the higher the volts the better the throttle response but it also richens the air/fuel mixture

 

SD TPSs are not adjustable AND DO NOT start drilling/elongating the holes to make it "adjustable" - you'll start to cause problems. On SD ECMs, the ECM does a calc based on the TPS to get a baseline and then computes % of TPS opening which is used in the programming.

Steve, have you readjusted your IAC? If not, go to the FAQs and do that. BUT DO NOT start trying to adjust your TPS. You do not do that on SD systems.

 

Well I wnet through a few more TPS sensors before I gave up and then when I went to the mini-gathering here in houston I talked to Barry who suggested that it could be the EGR valve and I never thought it would cause a stumble like that but I finally checked yesterday and unhooked it and plugged it and no more stumble and it feels a lot faster from a stop because I can easily scratch the tires without powerbraking, it feels like that boat I was pulling is gone and accelerates with ease.