I think I have read the answer to this but can not find. 94, 7.3 turbo, auto 93K. The overdrive lite keeps flashing, long time (higher rpm shift point) between shifts, when eventually shifts, give you whip lash. Just started this am, any help would be appreciated.

 

Does your tach and speedo work flawlessly any jumping around ........ what color is the FIPL (tps) on the IP.

 

Tach and speedo are fine

 

Check fluid levels! Could also be speed sensor (that is what they call them in gassers) related. Someone can speak better to the speed sensor issue.

 

When this happened to my Dad, flashing meant mechanical failure. New tranny time.

 

Well, seems a though no one has had this problem before. Fluid levels fine, drove this am and the trans seems to be working fine, no slipping just long(between shifts), rough shifting. So I am inclined to look at something electrical.

 

The first time my OD light started blinking it was the Tach/RPM Sensor. I don't have a tach in the van, so I don't know if it affects the tach readings.
The second time was after I replaced the IP. I didn't get the FIPL/TPS sensor adjusted right.

You can trouble shoot the RPM sensor by unplugging it and checking the resistance across the terminals. Resistance should vary with engine speed.
The FIPL/TPS can be checked by reading the voltage off the center wire with the key on engine off. You should get just under 1 volt at idle, make sure to disconnect the fast idle solenoid. I set mine at .98 volts and she shifts great. There is another wire on the FIPL you should check, but I can't seem to find the specs or remember which wire it was.

Vehhicle Speed Sensor/VSS and MLPS are also common culprits.

VSS can be checked the same way as the RPM sensor. Mine is in the rear diff. I raised the wheels off the ground, unplugged the harness, hooked long jumper wires between the sensor and ohm meter (so I could take readings while sitting in the seat), put truck in gear and take reading. They say to make sure you get atleast one up shift.

MLPS can be checked also, but I can't find the specs on those either.

Hope that helps and good luck.

 

This is a post by DieselDon I have taken the liberty to trim slightly.......

Hook up the negative lead of the volt meter to the battery ground and the positiove lead to the center GY/W ( grey/white wire which is the FIPL signal wire, I use a paper clip up the side of the wire in the connector. The FIPL must be attached to the wiring harness. Engine low idle speed must be set to specs prior to adjusting the FIPL. Engine off key on........

With a warm engine, key on, engine off measure the voltage at the GY/W wire, if adjustment is required loosen either the bracket with bolts or just use the slack in the Torx screw holes. Now gently rotate the FIPL until you get some where between 1.05V and 1.1V. then tighten the torx screws or bolts which ever you loosened ensuring no movement of volt setting . Rotate the throttle lever to WOT see if you get 3.8 V but not more than 4.3 V.

The FIPL mounting bracket can be moved but ensure it is centered for a good rotation. Any adjustment should be made by only rotating the FIPL. If a new FIPL is required, check tang engagement as you take off the old FIPL and then make sure that the tangs in the new FIPL engage the throttle lever properly.

The closed throttle voltage: 1.1 V, .........wide open throttle voltage: minimum of 3.8 V but
not more than 4.3 V.


DIESEL FIPL SENSOR INFO

DATE 1992

REASON
Early Black FIPL has High Failure Rate

RECOMMENDATION
Always replace the black colored early FIPL or any colored FIPL having 60 thousand or more miles with the late gray colored FIPL.

PART NUMBER
F2TZ-9B989-C

 

FIXED!!!!!! thank you all for replying to my thread. It was the speed sensor in the rear end. My meter broke so this am went to buy another to do all the V checks. Stopped by the ford dealer and asked (good thing living in a smallish town the parts guy will talk to you) about sensors - "try the rear sensor first". Well for $31+ change I purchased, new design. Installed, now every thing is back to diesel heaven. Just a note, the 94 with digital milage odometer has 2 sensors, one in the rear end and one in the tranny. Tip on changing - do not remove the connector, un do the 1/2 in bolt, remove the sensor then remove the connector, saves breaking off the locking tabs.

 

Sorry forgot to add Disconnect batteries, then re-connect. Gets rid of the error codes. Must be dying to drive a smoooooooooooth shifting diesel.