this truck a 93 f150 XLT 302 4x4 with the AOD trans

throws a code 23 TPS out of test range and a code 12 rpm self test unable to reach upper limit

it has a new map sensor, egr system checked, tps checked and passed timing checked

it has a knock that appears under heavish acceleration

if at cruising RPM you come upon a long hill and wish to maintain speed it will not respond to the throttle,
(no significant change in RMP between 20% of the throttle and the floor with bad rattle and knock )
it will bleed speed until it begins to miss and bog down.

you can physically peg the pedal too the floor and the truck will down shift and run up the hill until it up shifts again and bogs and bucks again.
or you can manually shift the auto trans and it will pull up the hill.

by then in most cases the road levels out and it will run normally but with a lack of passing power.

the logical place to start is the TPS but it has been checked twice by two mechanics and has passed both times so... I am at a loss.

 

I have had this truck in two shops 4 times,
I had it tuned by a dealer,
and tried unsuccessfully to get a 'data stream ' run at the dealership on a second visit but their equipment would not work,

3 local dealers no longer have the code machine needed to read this trucks mind
I have pulled these codes using the flashing light and buy an after market reader.

I am desperate to sort out this truck

 

I wonder if you have a partially plugged catalytic convertor. It's a guess since you have TPS codes and bogging and power loss.

After driving, see if the catalytic convertor is unusually hot (sometimes they will even get a little "red hot" when plugged).

 

thanks for the reply,

I drive the truck 50-100 miles a day so if that were the case I believe I would have been aware of it.
there does not appear to be excessive heat in the cat.

I believe it has to do with the trucks ability to process some kind of sensor information that affects how the truck delivers fuel too the cylinders.
(but I am the son of a guy who owned parts stores before chain stores destroyed the universe.... not a mechanic)

If the TPS signal is good at the sensor itself .... then where does that info go next

why does the code 23 (tps signal voltage out of self test range) in KOEO and KOER remain ever present.

Could there be a TPS signal, one that produces a sweep on the dial when tested by the mechanic, which passes the mechanics visual test. Even though the voltage is too low, thus starving the truck of fuel?


At this point I really want to understand the 12 code...(unable to reach upper rpm test limit) KOER code. If I assume at least one of the two mechanics who have tested the TPS sensor got it right and it is good. Then what systems and sensors does the truck's computer use too test the upper RPM test range?...as that is the other ever present trouble code.

there is no tach... where does the truck get its rpm info for timing and fuel delivery?

 

I would probably try a new TPS. The TPS is just a variable resistor. The normal TPS voltage range is 0.50V (closed) to 4.50V (open). If you have a dead spot(s) in the resistor windings, the dead spots will provide a "0" resistance reading to the computer. A "0" resistance reading tells the computer to not to inject fuel. This will cause engine bucking and or pinging at higher RPMs and while under load. You can disconnect the TPS and use a DVM to meter the resistance checking for a dead spot(s). A new TPS would be about $30-50.