For the early year guys:

My early 99 had a jerky throttle at light loads so what I thought would be a simple and cheap fix turned out a little different. All I could come up with on an exhaustive search was a Ford part # for a direct TPS replacement alternative rather than buying the whole pedal assembly for $400-$600. I think they are discontinued now anyway? The supposed part # was DY-967 for the common motorcraft TPS sensor. I bought one and installed it to find it was DOA, and supposedly that is pretty common? EDIT: sensor was not defective, see post #6. Even with the sensor unmounted it triggered a CEL and there were only a few rotational degrees that the CEL didn't illuminate. I took a chance and went with a NAPA (Echlin) part # 2-19093. My experience with their electronic parts has been more favorable than the other competitors' junk.

I mounted the new sensor and plugged it in to hear a SNAP when working the pedal. The internal spring mechanism broke so I got a replacement and decided to pull the pedal to see if anything fishy was going on just in case. Upon careful examination I see this - and wouldn't you know, I see a problem -




Note that the oem is female and the alternative part is male. Sure you can put the blade of the pedal shaft in there, but it will be too far advanced - or retarded since I apparently screwed up on the first one and the blade was on the wrong side of the tabs in the tps forcing it to break internally. So the fix is to reclock the TPS somehow or an engine light will come on and have nothing but idle speed.

My solution -




It is evident the (male) slotted shaft can be reclocked fairly easily -






Press the shaft out and rotate it clockwise. Relative to the plate the shaft needs to be rotated about 43 degrees. Press the shaft back into the plate with a vise and deep well socket. Take note the depth the plate needs to be pressed on for proper alignment. The idea is to have the shaft blade just make contact with the TPS ears when the sensor is lined up with the holes and centered in the plastic keeper.

The shaft will probably stay put, but it isn't going to be a factory tight fit. I TIG welded the plate to the shaft, it isn't moving.






The shaft has been re-clocked, I measure 43 degrees and it is dead on where it needs to be.


Below is the correct modified orientation of the bladed shaft.





And the final product, that works...






As for the idle validation switch, there should be enough miniature microswitches out there to match something up and retrofit it into the same location. That will be another day.

Again, the motorcraft part # is DY-967 so any crossover part of your flavor should be a direct fit. I'll probably grab a spare to throw in the truck. Keep in mind the original sensor will not work after this.

 

Great write up and pics, reps! Thanks for documenting a method to engineer a way out of that jam.

On edit: @Y2KW57 Miscellaneous forum issue; Tried to rep but dialog box stopped it, text something like "this thread has rec'd no reps yet, you have xxx rep points".

 

Greasemonkee, well done sir!

David, I sent a rep to Greasemonkee on your behalf and it worked for me. I am using Brave browser on a Windows 10 OS.

@Y2KW57 , tagging in order to have this thread considered for the 7.3L PSD Tech Folder. I feel as an FTE'r this has some valuable information that may be of great use to someone in the near future. Images, procedures and part numbers! (Done.)

 

Excellent work Greasemonkee! I actually ordered and returned a DY-967 because I couldn't figure out a way to get it to work. Kudos to you for your persistence.

Do the factory sensor and the OEM sensor have the same resistance at full sweep? They're potentiometers, right?

Edit: The FSM calls it the Accelerator Pedal Position (APP) Sensor. Tagging @Y2KW57 for Tech Folder Content (Done)

 

Nice! I returned my DY967 as well thinking it would not work. I've been left buying Dorman TPS's and/or Standard pedal replacement off rock auto through the years. I would love to return to MC sensors here too going forward. Reps incoming!

 

I decided to retest the new Motorcraft DY967 F4SZ-9B989-AA sensor on the pedal just to make sure the PCM rejected it. I was wrong, the check engine light does not illuminate when properly clocked and mounted to the pedal assembly. Hanging loose and unmounted it did trigger a CEL, but not mounted. This is quite interesting and confusing, but glad to say it wasn't defective after all. Noted on original post.

We all know that benchtop resistance checking should only be used as a rough and inconclusive diagnosis for troubleshooting these units, but here are the numbers I observed:

Sensor oriented with plug on the right, looking at the front/outside -

Original motorcraft top two terminals: idle position - 124 ohms, max position - 3.58 K ohms
Original motorcraft lower two terminals: idle position - 3.83 K ohms, max position - 320 ohms
Original motorcraft outer two terminals: 3.76 K ohms

The other two sensors I tested vary as much as a few hundred ohms, even at the idle position so apparently there is a pretty broad range that the PCM will accept? Or maybe not, once the sensor in mounted...

 

APP Sensor Circuit, PCM Pin 89 (Ground Pin 24)

Operating Range: 0.5v - 4.95v

Key On: 0.5v - 0.7v

Low Idle: 0.5v - 1.6v

High Idle: 3.4v - 4.95v

GTOR: 0.5v - 1.0v

(GTOR = Garbage Tune Operating Range)

 

You mean because of something like one of these?

https://roarpedal.com/products/roar-...UaAk0fEALw_wcB

 

It is so strange how all things devolve.

Tattoos used to be looked down upon as prison garb. Now we see models for Fortune 500 companies covered in tattoos.

Women at one time were forbidden to wear pants in public by many dress codes of days gone by. Now we see women wearing nothing more than paint (literally, just paint) as they walk down the street checking to see if anyone notices.

And the "big secret" in the aftermarket tuning industry at one time was the seat of the pants boost that customers would rave about when their foot touched the throttle pedal. "Wow, so much quicker response" they exclaimed, as victim after victim of this ruse shelled out $500 a pop for the range of voltage to be reduced on their APP / TPS controls on drive by wire vehicles, entirely unbeknownst to them. They "felt" more power sooner, so they believed the tuner magically delivered more power for their money. They could have gotten the same power by flooring the accelerator. And of course, if they realized that, they would not pay a tuner $500. So the tuners kept this quiet (most did, except for a few honest ones). Sort of like not wearing pants or tattoos in public, tuners just didn't talk about this trick.

But now, this trick is actually put in a black box and boldly advertised for what it is. A Go Pedal Gizmo. Advertised as such with absolutely no shame.

 

Even Ford is guilty of this within the run of the 7.3 though. About the time they realized that the 300 HP Duramax was a formidable opponent against an already 8-year-old platform that was beginning to show its limitations, Ford made the pedal response of the 02 275 HP 7.3l a teeny bit quicker off idle to make it feel more powerful.



The reason for this is pretty simple though. ACTUAL tuning for most of this brand new stuff either isn't available nor is it practical. You're starting with a platform now that has far more power than it really needs yet also is laden with unfathomable amounts of emission controls that cannot be bypassed legally. Actually, it's always been illegal to modify emission systems so these companies are simply working within the limits yet still make the vehicle more sprightly without defeating the systems designed with feelings and emotion rather than logic and reason.