If it's a scratchy pot the potential is there for it to not be doing it when you're checking it out. IOW could be worth switching out just because.
don't know how much this applies (different model and part #, but the ohms should be the same)
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Wrong Gear Starts
Bad or mis-adjusted MLPS
Can cause wrong gear starts, no upshift, falls out of gear, and high line pressure = harsh upshift and engagements. May or may not set code 67/634 (MLPS out of position).
Note
MLPS is located on driver's side of transmission case.
MLPS adjustment
Place manual lever in Neutral. Line up I.D mark on sensor with l.D. mark on plastic bushing. Tighten bolts.
To check MLPS
1. Hook red lead of DVOM to pin # 199 (MLP sensor signal).
2. Hook black lead of meter to pin 359 (sensor signal return).
3. Set meter to ohms.
4. Move manual lever through the different positions and compare DVOM reading to chart below.
Manuel lever position
Meter should read:
P 3769 to 4608 ohms
R 1304 to 1593 ohms
N 660 to 807 ohms
D .... 361 to 442 ohms
2 190 to 232 ohms
I 80 to 95 ohms
Important
If the MLPS needs replacement, use Ford part # E5TZ-7A247-A. This kit includes a new style harness connector. You must replace the connector to use the new MLPS. By sliding the old wire separator from the original connector up the harness you can leave it in place as you install the new connector. This helps to keep the wires in their original location.
Note
Make sure you clean the harness connector with brake clean and apply some dielectric grease to the pins. This will ensure a good connection. Use Permatex part # 67V (dielectric tune-up grease). You can get it at most auto parts stores.