1989 F250 302FI 4X4.TPS adjustment in Ford manual is 0.9-1.1 volts with throttle closed, I checked mine and it is 0.86 volts. ? Is this setting okay, have lack of power in 3rd and 4th gear (manual tranny) and absolutely no throttle respone in 5th.Could the 0.04 volt difference really affect throttle response? WOT reading is above 5 volts. This horse just does not want to get up and go. Any suggestions apreciated. FARMERBOY

 

Adjust the TPS and then pull your codes. Visit http://fordfuelinjection.com/?p=13 to learn how. OR you can see if your local parts store will pull them for free. I'm sure they'd be happy to sell you a code reader should you prefer that. But really, all you need is a paperclip and the ability to count.

Post your codes back and we'll be glad to help further.

Tim

 

0.86 should be alright. I would check to see why it is going over 5V at WOT. 5V should be the absolute max since the input voltage is 5V.

 

As EPNCSU2006 said the max is below 5 Volts as the voltage regulator inside the EEC puts out 5 Volts and you will have voltage drop in the wires .
So if your reading is 5V or above you have a bad EEC and it needs to be replaced as nothing is going to work right, or your meter is inaccurate.

 

If the 5-Volt supply were above 5 Volts you might have a bad filter Cap, the bad filter caps would either be C2 or C4.

Here is a diagram of the 5 Volt Supply.

 

While we're on the subject of the TPS, I have a voltage question. Mine is at .9V, and 4.8 or so at WOT. I have the high idle thing still going on, but was wondering if the .9V value itself could be part of the high idle? If I were to adjust it to, say, .7V, would that lower the idle at all? Or anything below 1V is all the same?

 

The .9V, and 4.8 or so at WOT are the normal voltage readings.
The voltage from the TPS has to do with how much fuel is injected (how long the injector stays open).
The EEC manages the idle speed with the IAC valve (or what ever you want to call it) and uses the IDM pulse train to set the Idle.
If air gets around the IAC then you have higher Idle.
Air can get around the IAC in a lot of ways, vacuum leaks, throttle plate shafts or maladjusted throttle plates.
Vacuum leaks can be hoses, intake gaskets, injector "O" rings or other gaskets like the throttle body.
Of course the IAC itself can stick open or open too far for the signal it is receiving.

 

Farmerboy again. Was able to adjust tps to specs .97 closed and 4.6 volt WOT. pulled engine codes but the list was too long to list, Know some where problems arready fix, will wipe codes and drive for a day then check the again. Took it for a test drive but there was no difference in power, guess that wasn't the problem .
THANKS for ALL the IMPUT it really does help to know you guys are willing to pass on your know how! farmerboy

 

I just bought and replaced my TPS today. I looked in to them also before i bought one just to get a good deal. ANYWAY, I have found that they are not adjustable. AT least motorcrafts and the one at O'Rilley's i looked at. Mine was below and above required spec's. I think it was code 53 and 63. I got one for $40. I recommend just buying a new one. I took the throttle body off and just unscrewed the one on there and slapped the new one on, put the rest back together and it runs drives like it should. its great.