I had my car taken into Lexus yesterday for an engine diagnosis, well today I got a hold one of the service reps and he informed me that I had a shot throttle position sensor. Unfortunately Im 18 and dont make enough to just shell out the money for Lexus to do their ''magic'', nor will my parents help me out, so I would like to replace it myself. I have general knowledge and how to on Supra motors (previously owned a 7M-GE MKiii Supra) and my neighbor is a lead technician at Lexus. My question is, with your average tool set and professional help, is this something I could do succesfully in my driveway, or does it require any special tools or measuring that I should let Lexus handle?

If anyone has ANYTHING helpful to add, please do so. I would just ask my neighbor who is the mechanic, but unfortunately he is as work (cant get a hold of him until after 5:30) and Lexus gave me until 5:30 to let them know what I'm going to do with the car. Thanks.

 

it will be very easy it is right there on top of the throttle body two bolts and a wiring harness. the bolts are 10 mm. it should take you about 15 min. i did mine last spring and it was easy. it took longer to drive to get the part.

 

I remember having a problem on my Supra regarding the TPS and how the degree it was mounted at. The position, or angle/degree the sensor is mounted, wont effect the rpm the car idles at? Or is it just a trial and error type of thing....install it, idles too high, adjust it, etc, etc, until it's fine.

 

hmmmmmmmmmmm. cant help you. i have no clue about that. i just put it on and it works great. i had to make sure the tabs grabed the throttle body but other then that it idels fine. i remember a thread where some one asked what there car idles and mine was on par with everyone else.

 

It has to be setup with a multimeter. and a feeler gauge

 

the tec at sewell never said anything to me about that. i guess i just got lucky . do you think i should take it in to get looked at. just to make sure i got it on right. it has been a long time and have put 15,000 miles on . could this be a bad thing. i was talking with one of the tec when i got it from sewell and he never said a word when i told him i was doing it. now you got me worried

 

It wouldn't hurt to check it, as if it's off either way it will idle high or low. You need a .50mm(.020in) feeler gauge. Set the feeler gauge between throttle stop screw and stop lever. Measure resistance with meter between the top 2 terminals of the TPS (with the connector unplugged). Turn the TPS clockwise till the meter deflects(reads infinity), then tighten the 2 screws for the TPS. Next using a .40mm(.016in) feeler gauge the meter should read continuity. Then use a .60mm(.024in) feeler gauge and the meter should read infinity or no continuity. if it's off readjust with the .50mm feeler gauge till you get it right.

 

If you put the throttle position sensor on wrong would it throw another code for a closed throttle position switch malfunction?

 

So I figured it out. I hooked up a scantool from one of the techs here, and it shows the % of the throttle along with the throttle position switch. So the Position switch was off the whole time because the throttle had more than 12%, at 10+ percent the throttle will stay open. So I had to re-adjust my TPS to get the percent to read 5%, for some reason no matter how much I turned it, it wouldnt go below 5%.
No check engine lights though, so its all good.

 

Does any one know of the factory setting for a TPS Sensor on a 95 GS300

 

From alldata:

1.Inspect Throttle Position Sensor.




(a) Check the vacuum at each port.

•Start the engine.



•Check the vacuum with your finger.
•Apply vacuum to the Throttle Opener.
•Insert a thickness gauge between the throttle stop screw and stop lever.
•Using an ohmmeter measure the resistance between each terminal.
Clearance between Between Resistance
lever and stop screw terminals
0 mm (0 in) VTA1 - E2 0.34 - 6.3 k ohms
0.40 mm (0.016 in) IDL1 - E2 0.5 k ohms or less
0.60 mm (0.024 in) IDL1 - E2 Infinity
Wide open throttle VTA1 - E2 2.4 - 11.2 k ohms
Always VC - E2 3.1 - 7.2 k ohms

2.If necessary, adjust Throttle Position Sensor.
•Loosen the 2 set screws of the sensor.
•Apply vacuum to the Throttle Opener.
•Insert a 0.50 mm (0.020 in.) thickness gauge. between the throttle stop screw and stop lever.
•Connect the test probe of an ohmmeter to the terminals IDL1 and E2 of the sensor.
•Gradually turn the sensor clockwise until the ohmmeter deflects, and secure the sensor with the 2 set screws.
•Recheck the continuity between terminals IDL1 and E2. With 0.40 mm (0.016 in) clearance between lever and stop screw you should measure continuity.
With 0.60 mm (0.024 in) clearance between lever and stop screw you should measure NO continuity.



3.Inspect Sub Throttle Position Sensor, Sub Throttle Actuator and Sub Throttle Valve (vehicles with TRAC only).
•Inspect Sub Throttle Actuator. Using an ohmmeter measure the resistance between the terminals ACM and A, ACM and A-, BCM and B, BCM and B-.
Resistance: 0.5 - 1.0 ohms



•If the resistance is not as specified, replace the Actuator.
•Inspect the Sub Throttle Valve. Remove the four screws and remove and Sub Throttle Actuator. Verify that there is no clearance between the throttle stop screw and throttle gear when the Sub Throttle Valve is fully closed.
•Inspect Sub Throttle Position Sensor. Insert a 0.30 mm (.012 in) / 0.50 mm (0.020 in) feeler gauge between the throttle stop screw and Throttle Valve gear. Usng an ohmmeter, measure the resistance between terminals as indicated below.
Clearance between Between Resistance
lever and stop screw terminals
0 mm (0 in) VTA2 - E2 0.34 - 6.3 k ohms
0.30 mm (0.012 in) IDL2 - E2 0.5 k ohms or less
0.50 mm (0.020 in) IDL2 - E2 Infinity
Wide open throttle VTA2 - E2 2.4 - 11.2 k ohms
Always VC - E2 3.1 - 7.2 k ohms

4.If necessary, adjust the Sub Throttle Position Sensor (vehicles with TRAC only).
•Loosen the 2 set screws of the sensor.
•Apply vacuum to the Throttle Opener.
•Insert a 0.40 mm (0.016 in.) thickness gauge. between the throttle stop screw and Throttle Valve gear.
•Connect the test probe of an ohmmeter to the terminals IDL2 and E2 of the sensor.
•Gradually turn the sensor clockwise until the ohmmeter deflects, and secure the sensor with the 2 set screws.
•Recheck the continuity between terminals IDL2 and E2.
With 0.30 mm (0.0162 in) clearance between lever and stop screw you should measure continuity.
With 0.50 mm (0.020 in) clearance between lever and stop screw you should measure NO continuity.



5.Reinstall the Sub Throttle Actuator with the four screws (vehicles with TRAC only).

 

Thanks a bunch