Let's diagnosis a failing throttle position sensor on our revival F-150!
Are you having check engine lights (Ford code 121 and 124), weird drivability, dead spots in the throttle or down on power? Well those symptoms are exactly what was happening on our 1995 Ford F150 project truck.
Unfortunately the TPS is underneath the throttle body, so the first thing we did was remove the black air intake tubes connected to the throttle body. Remove the evap purge valve, coolant lines, disconnect the IAC (idle air control valve) and the TPS sensor plug.
Once you have you throttle body removed you can access the sensor located on the bottom of the housing. I planned on a replacement sensor but I was still curious what the voltages looked like and performed a sensor test.
Here's the wiring guide for 87-97 F150/F250/Bronco 5.0L/302
Black - Ground
Green - Signal Sense
Orange - Power (5V)
When at idle you want to see under 1 volt. I believe Ford's run best with a closed idle voltage between .90 and .99 volts. To get this I had to drill out the TPS sensor holes just slightly to get enough adjustment to make that happen. You also want to see a very linear movement when you slowly open the throttle blades - 1.1, 1.2, 1.3, etc. all the way up to 4.5 -5v. This will get you the proper calibration the computer needs to determine the blade position.
Reassembly is the reverse of installation after you give everything a good cleaning. I also cleaned out IAC valve to make sure it was moving freely. The throttle body bolts need tightened between 13 - 15 lb-ft or a firm hand tight.
And that's it! Enjoy your better running truck!
#obsford #bronco #throttlebody
Ford F series trucks and Broncos from 1980-1997.
1991 Ford F150
1992 Ford F150
1993 Ford F150
1994 Ford F150
1995 Ford F150
1996 Ford F150
1997 Ford F250