Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: hellsing73 on September 29, 2009, 06:39:12 PM

Title: tps
Post by: hellsing73 on September 29, 2009, 06:39:12 PM
i need help finding out if my tps is bad or not. a book i have told me to check the 89 and 90 terminals with an ohmmeter but it dose not tell me what 89 and 90 are on the tps.
Title: tps
Post by: grutinator on September 29, 2009, 08:18:36 PM
prod the green wire at the tps with a voltmeter. ground the black prod of the voltmeter. with the key on engine off, it should be between .8 and 1 volt. if that checks out, slowly move the tb towards full open and the voltage should slowly climb till it reaches about 5 volt.
Title: tps
Post by: hellsing73 on September 29, 2009, 09:17:05 PM
what? that dose not make much sences to me. the + of the meter to the green wire and - of the meter to a ground?
Title: tps
Post by: BadShoe on September 30, 2009, 12:27:07 PM
grutinator is telling you right. The green wire should be the signal wire.
Title: tps
Post by: hellsing73 on September 30, 2009, 01:35:43 PM
i never said he was lieing to me. i just dont understand the way he said it.
Title: tps
Post by: thunderjet302 on September 30, 2009, 03:34:17 PM
Stick a pin in the green wire and stick a pin in the black wire of the tps. Connect the pin in the green wire to the positive lead of the volt meter, connect the pin in the black wire to the ground lead of the volt meter. Measure the voltage KOEO. As long as it's between .6 and 1.0 volts you are fine.
Title: tps
Post by: grutinator on September 30, 2009, 04:12:30 PM
yes. but also if your worried about it having a dead spot or something you can also slowly turn move the throttle body and watch the voltage climb to around 5v.  i guess i didn't explain well.
Title: tps
Post by: hellsing73 on September 30, 2009, 04:36:43 PM
i got most of what u said just was not sure. so thats why i asked lol and thank you for the help
Title: tps
Post by: BadShoe on October 02, 2009, 11:15:58 AM
The TPS is a sensor with a ground wire (signal return), voltage wire (reference 5 voltage) and the green signal wire (the wiper that runs across a resistor tied between the ground and 5 voltage pin). At idle the wiper is resting near the ground side so the signal wire will show low, about one volt. As you open the thottle the wiper goes toward the 5 volt pin making the signal wire gain voltage. At WOT the signal voltage will be high about 4.5-4.8 volts. You should not see 0 or 5 volts on the signal wire however because the wiper does not reach all the way to the ground or 5 volt end of the internal resistor. Signal voltage of zero or 5 volts or eratic readings as you open the throttle, indicates a possible bad TPS.