I have an '02 F150, 5.4 (VIN L), FX4 with 212,000 miles. About two months ago my truck started "surging" while passing cars from cruising speed, so following advice on this forum, I checked the throttle position sensor for erratic sensor voltage. The voltage climbed smoothly at first, but at about mid throttle, it would suddenly drop, then return, then drop more, then return (in other words, it was bad). I replaced it, and then ran the test again just to confirm my diagnosis. The new one worked flawlessly.

A couple weeks later my SES light came on again, and the truck was gutless. I had the codes read (1120, 0122), and so I checked the new TPS. This time not only was there some erratic readings, but the reading at wide open throttle was only 3 volts (at least a volt low). I checked the 5 volt feed to the sensor and it was fine. So, I, you guessed it, replaced the TPS again, and the problems went away.

Well, yesterday my truck started showing the all-too-familiar symptoms of a bad TPS, so out came the multimeter, and, bad again!

Is this just a coincidence, or has anyone else had a similar problem? Any ideas?

 

did you replace the tps with a motorcraft replacement? these ford trucks don't like any sensors that aren't motorcraft.

 

I had a short lived aftermarket TPS. However I don't think it was a case of my FORD truck not liking "any sensors that aren't motorcraft". The el cheapo TPS worked just fine for awhile. New intermittent symptoms developed, that didn't seem like the previous TPS issue. When it finally threw a fault code I could hardly believe it was the 'new' TPS. I broke it open to see if I could find the fault. Sure enough, cheezy construction resulted in a fritzed internal connection.

 

That probably is the issue, all three were from third-party manufacturers. If...I mean, WHEN this new one goes I'll make sure to get its replacement from a dealer.

Thanks for the tips guys.