I'm needing to put a new TPS on my 1986 F150 302 EFI. My Hayne's book says to adjust it until the voltage reads 1.0 V. However, I don't see how this can be mounted except exactly one way. It has two holes for screws and when you put those through, even loosely, there is no give to turn. The part that is turned by the throttle is inside the case that mounts with the screws.



The two yellow arrows point to what engages with the tangs that extend out of the throttle body.

The book says there is no adjustment needed on the 6 cylinder. Maybe they made a mistake and the 302 V8 doesn't have a means of adjusting either. I would appreciate anyone's help with this.

 

There is a little bit of movment, not much. I have had to break out the rat tail file in the past and open the holes up on aftermarket units. As long as no one has dicked with the base idle screw, a motorcraft unit should be about dead on.

 

Thanks. I reemed the holes out a little and was able to adjust it to 1.04 volts. The truck seems to run and idle fine now, a lot better than when I limped home with it.

 

As Archion said, the only time a TPS should need adjusted is when the base idle screw is adjusted. This is why factory replacement TPS units do not have enlarged holes that allow you to adjust the TPS. I sure hope the TPS screws on the older trucks are easier to remove than the newer Fords. For some reason Ford decided to locktite the screws on the newer vehicles, and the only way to remove them is with vise grips when the screw is hot, or cut the heads off and then remove the screws with vise grips.

 

1.04 is still way too high. Your idle screw has been dicked with. Needs to be .9 to 1.0 Max. You need to look up setting the base idle on your motor.

 

Thanks for the posts. As far as the TPS, I had to remove the throttle body to get to it, and yes I had to use my itty-bitty vise grips to turn the screws. I'll see how it goes. I don't know how accurate my meter is; the battery connector broke on my Craftsman meter and I could only get a cheap China-made one at Harbor Freight. I had read somewhere that 0.1 volts was the accepted tolerance on the base setting of these TPSs, so I thought the 0.04 volt overage would be OK.

 

.01 was enough to actuate and flutter the solenoid bank for the egr on my truck. As wella s throwing the mixture off. The ecm thought it os off-idle so time to open the EGR... didnt make for a good running truck...

The procedure I came across a while back was to disconnect the IAC and set the base idle @550-650 rpm that way, and then revisit the TPS voltage. Should put you in the neighborhood.