Bad ones cause surging with auto's on the freeway, manual tranny's would also benifit from the cleaning but wont notice the affects. you MAY see a slight bump in mileage as the PCM wont think your foot is mashed to the floor intermitantly anymore (no noise).
4.7 motor in my Dak... had a bad surging problem on the freeway and as we all know it's the TPS. So having nothing to loose, I yanked it out, drilled a small hole large enough to fit a spray tube for a can of CRC electronic components cleaner and sprayed it in until I felt there was enough in there to clean it... I then turned the TPS shaft several times to clean the contacts on the inside. Dried it out, slapped it back in, took it for a drive and bam... no more surging. rock solid on the freeway now.
SO now we have a fix for the TPS sensor. This will work for the 3.9/5.2/5.9/4.7 motors and probably the 3.7 & 5.7 motors as well.
When your done, put a very small piece of electrical tape over the hole and then cover the tape with silicon to keep the tape in place and to keep dirt out. I dont suggest filling the hole with silicon as if you need to access the hole again, you may push some that is in the hole into the sensor which could cause problems.
1. Remove TPS sensor from Throttle body
2. Drill a 1/8" hole in a spot where you will be able to spray in CRC Electronic Component Cleaner and the drill bit will not go in too deep too fast.
in other words... drill with a very light hand so you dont damage the contents of the sensor.
3. Spray the cleaner into the hole, dont be shy with it...
4. Rotate the sensor shaft so that the cleaner will get into the contact area's of the sensor.
5. Shake out the excess solvent until all of it is out.
6. Once your convinced it is dry, cover the hole with a very small piece of electrical tape and seal with silicon sealant.
7. reinstall sensor into the TB.
8. Reconnect the sensor electrical connector and your done.