The transmission in my 1990 F-350 project truck hunts and rattles when switching from 2nd to 3rd. Sometimes it switches without hunting and just rattles and somtimes it switches just fine. I just changed the fluid and filter including draining the torque converter (15 liters). Any ideas?

 

Does the RPM guage run steady, how about the speedo........ever reset the FIPL on the IP.

EDIT I would also check the 4 bolts on the flywheel/convertor for tight, you can see them by dropping the TC cover on the bellhousing and rotating the flywheel. Disconnect the fuel shutoff solenoid on the IP first, don't want a stray start condition, not likely but safety first.

 

Question for PLC7.3, what is the FIPL on the IP, and how and why would you reset it?

Phish

 

Fuel injection pump lever (sensor) is known as a Throttle position sensor on a gasser, it sends a variable voltage to the (PCM) powertrain control module to indicate what position the (IP) injector pump lever is at. The FIPL info and the RPM sensor info along with Speed sensor info allows the PCM to tell the trans when to shift and how. If any one is missing or out of spec the trans does not work correctly and may go into Limp mode....... 2nd gear and reverse only, just enough to get you off the interstate or to a garage/safe place..

To reset it .........

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 positive 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.
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 loosen and 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. There must be no dead spots from idle to WOT so watch for them.
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

 

PLC7.3, thank you vm.

Phish

 

Hmm, maybe I should be looking at replacing the wiring harness that the FIPL is connected to. The previous owner had cut back the wire loom on this harness which I believe incorporates the charge system harness and while doing so he cut through the the wire sheathing. All of the wires on this harness had turned green inside from corrosion and I already cut out and soldered in some patches. I'm going to look into a new harness tomorrow just in case I didn't get rid off all of the corroded wires and there is some resistance giving inaccurate FIPL readings. Thanks.

 

Did my tests.....

Closed throttle- 0.99v
WOT- 4.03v

 

The big thing is to have the engine warm and the idle set to spec. for the auto that is usually 650 in gear (curb idle). The with KOEO do the test.