2000 F150 with 5.4L . Trying the TPS adjustment (adj to ~.995 ) mentioned in other threads to go along with AirForce One intake recently added.

Anyone got any hints on a good way to get the bottom screw on the tps to turn? I was able to loosen the top with a socket wrench w/ screwdriver bit, but can't quite get a good straight angle on that bottom screw. I did loosen the assembly directly to the right of the TPS in order to get the socket wrench down in there and still couldn't get a good 90 angle on the screw. I didn't want to totally remove that neighboring assembly unless absolutely necessary.

One other thing... the voltage meter I'm using won't settle on one particular voltage. I used the pin through the wire trick to hook into the TPS wire, and I'm using the frame as a ground. The voltage jumps around and will never settle on a specfic number. Is this a problem with the meter, or am I doing something wrong?

Thanks in advance!!
Tom

ps.. if anyone needs a good laugh... I've managed to drop not 1, but 2 of those screwdriver bits down onto the engine in the process. I didn't laugh at the time, but it's kinda funny now.

 

It doesn't surprise me that you're having trouble. The TPS (as in throttle position sensor??)) screws have glue on the ends. I stripped mine bad. The vise grips is the only thing that worked.

 

tesexton,

If your pin thru the wire is making good contact and the ground probe is making a good ground the volt meter should be steady if your not moving the tps control. If the voltage is moving and your not moving anything just standing there watching the voltmeter, then its time to replace the tps control. Its nothing more than a varible reostat and can develop dead spots thru-out it's operating range of motion.

When you say the voltage changes, how much? It will change a few thousand'ths, but not tenth's of a volt.

If you watch the voltmeter while working the throttle from closed to wide open the voltage should increase very smoothly to 5 volts.

Gene

 

Can someone point me to the direction of the thread he was reading. I was told that I probably need to adjust my TPS because of my airforce intake. What difference does it make in the motor?

 

Open up safety pins and slide the pin end into the back of the plug alongside the wire to make contact inside rather than poking the wire. This gives a good contact instead if just having the pin slide alongside the copper strands when you pierce the wire. Then slide the probes from the tester into the open holes of the safety pins and let them lay there. This way you don't have to try to hold the probes and make the adjustments at the same time. I loosed my upper bolt but couldn't loosen the bottom one. By taking the upper bolt out I was still able to move the TPS slightly by tapping it with a small rubber hammer.

 

Take the TPS off and measure its resistance while slowing opening and closing it. It should vary smoothly between low and high resistance. This will eliminate the PCM and wiring from the voltage variations.

PCM provides a 5V signal that is grounded through the variable resistor. This provides a varying voltage on the wiper. When you take it off, you won't measure voltage, just ohms.

 

Thanks for the tips folks. I was out of town this weekend, so couldn't complete the job, but hopefully I will be finishing up this week.

The voltage meter was all over the place, so maybe the TPS has gone bad. Of course, that leads me back to getting that bottom screw loosened. There is a plastic piece right next to the TPS that last time that I just loosened. Maybe this time I'll completely remove it.

Is replacing the TPS as easy as taking out the 2 screws, removing the old, and screwing in a new one? Does Autozone, etc carry these, or will I have to visit the dealer?


On another note, if anyone is interested, I had the dealer address the latest recall on 2000 F150s involving the cruise control causing trucks to catch fire. They just unplugged a plug in the engine bay and taped it up to disable the cruise control. It was on the driver's side of the engine bay pointing straight up. Said they would call me when the fix parts were available in approx April.

 

and here's the URL for the original thread:

https://www.f150online.com/forums/sh...ferrerid=37092