E4OD torque converter lockup issues

[aofarrell2]

Working on my new to me 1992 F350 with a IDI and an E4OD, and having some issues with t/c lockup.

Transmission has clean fluid at the correct level. Shifts fine and for the most part shifts are on time, although there is an occasional erratic downshift when lightly applying throttle and then it upshifts again immediately.

It shifts through all gears and into O/D just fine, and engine braking works in all gears. No flashing O/D light (and the light works). It will not lockup the torque converter unless I am going above 60MPH with the accelerator to the floor, literally it has to be at the floor for the t/c to lock. If I let off it unlocks immediately.

The RABS light is on, diff sensor is new as the old one was bad, speedometer works fine with no intermittent issues.

Am I wrong in thinking the FIPL/TPS is likely bad? Anything else I should check out?

Truck runs like a top, just a few minor issues here and there.

 

[SLC97SR5]

I would definitely have a look at the FIPL and set the voltages correctly.

I would also give your brake lights and brake light switch a look to make sure they are working properly and that the switch is releasing when your foot is off the brake.

 

[aofarrell2]

The brake lights work and the switch appears to release properly.

I should also mention that the cruise control doesn't work either, I don't know if that's related or not.

 

[SLC97SR5]

The RABS light is ON?

Does your tach work properly?

Check the fuse for the cruise control. If your Truck has had the recall performed the fuse will be in a harness near the master cylinder.

 

[aofarrell2]

Yes the Rear ABS light is illuminated.

Tach works and is never erratic.

What recall are you referring to? I was not aware of one for the cruise control.

 

[Thewespaul]

The one that burned down countless of these ford f series. There’s a tech article at the top of the page that goes through the recall

 

[aofarrell2]

Well I installed a new FIPL and adjusted it to read 1.2v KOEO at idle.

Shifts are still on time but lockup still only occurs with throttle nearly to or at the floor. As soon as I let off the throttle to less than 80% or so it unlocks immediately. Any ideas? Should I change the voltage and play around with that a bit?

Also, somewhere I read that lockup won't happen until the engine coolant warms up. Is that true?

 

[trackspeeder]

Well I installed a new FIPL and adjusted it to read 1.2v KOEO at idle.

Shifts are still on time but lockup still only occurs with throttle nearly to or at the floor. As soon as I let off the throttle to less than 80% or so it unlocks immediately. Any ideas? Should I change the voltage and play around with that a bit?

Also, somewhere I read that lockup won't happen until the engine coolant warms up. Is that true?

Lock up will occurs when the tranny is up to temp. It doesn't rely on coolant temp.
It can take a few miles before operating temp is reached.

 

[aofarrell2]

Figured out the lockup issue.

I was aware of LEDs causing issues. I didn't think this truck had LED lights on the rear as they looked like incandescent housings and lenses (you know how you can usually see the LEDs clearly). Well I figured I should check and see if a filament collapsed in a bulb, opened up the light and it was a non-replaceable LED fixture. Go figure. Got a load equalizers (6ohm) and installed it in series on one side. Fixed my lockup issue AND turned off my RABS light.

The clue? With key on and ALL lights off, the rear lights had a very faint glow. Apparently the computer check has enough voltage to very slightly illuminate LEDs, which we already know don't load the circuit enough and causes the TCM and RABS system to see a fault.

Oh well. It works now.

One question though, the shifts and lockup seem just a hair early. Its in 3rd by 35MPH and it'locks up almost as soon as it's in 3rd, and O/D follows quickly. Is this normal?

 

[1992 idi 73]

Yes the second you get pass 35 MPH you should feel it lock up right away. My 92 IDI does this all the time. It will not lock up as soon if you are ******* the throttle but that might be the **** kit in mine that keeps it from doing that.

 

[aofarrell2]

Yes the second you get pass 35 MPH you should feel it lock up right away. My 92 IDI does this all the time. It will not lock up as soon if you are ******* the throttle but that might be the **** kit in mine that keeps it from doing that.

Let's hope it's not a **** kit sorry, couldn't pass that opportunity up.

On another note, drove the truck 200 miles today, and noticed a random quick unlock and locked back up again. Im suspecting one of two things. Each time I turn on the turn signal it messes with lockup. Either my MFS is bad or I need a load equalizer on the other rear light too. Any thoughts?

Edit: noticed tonight that the brake light switch I just replaced keeps cutting out... Gotta be part of the problem. Ugh.

 

[Dirtleg]

Another possible intermittent loss of lockup can be a dirty or bad solenoid valve connector.

I thought mine was bad but it was just dirty. Was on a 900 mile drive and about 150 miles from home it started briefly unlocking at steady highway speeds. Figured I had a bad connector but it turned out be be just dirty.

Cleaned it and not another issue for the last 8 months.