TPS sensor question?

[Lt4-turbo]

My service engine soon light came on on my 86 GN. I checked the code and it was a 21( bad TPS). When I first put the new sensor in it idled perfect and the check service engine light didn't come on. After a couple of minutes the car light came on and the car started to idle to fast about 3,000 rpm. I adjusted the sensor some and it is now at about 2,500 rpm but the light still is on.
Can anybody tell me what I need to do next? I don't have a scan tool. Thanks, Jon

 

[scottyb]

Do a search. I recall a thread or 2 where someone had a wiring problem going to his TPS, and he chased it for weeks. Consider it.

Also, if you go to gnttype.org, it will show how to set the tps using a volt meter. It's possible the new one is not set within spec, so the ECM isn't thinking "idle", or maybe defaulting.

Don't mess with the throttle blade position until you get a scan tool and can set the IAC.

www.vortexbuicks-etc.com has some really good notes on TPS and IAC.

 

[Lt4-turbo]

Update. I checked the code again. It now reads code 22. Sensor is reading low. I think it is just out of adjustment. Is there any way I can adjust this without a scan tool? I am taking the car to a car show tomorrow and I need to get the light out. The car is idleing at about 1900 rms right now and is running good. Thanks, Jon

 

[SFITurbo]

Check http://www.vortexbuicks-etc.com/ for setting with a digital voltmeter proceedure.