E4OD converter doesn't lock

[76ford466]

It's been awhile since I've been on here had several personal issues like divorce but anyways back to the truck problem. Working on a friends 91 f350 with a 7.3 idi and auto. It was a real dog when I started, tps sensor was completely lose shifted horrible. Filter stopped up and four injectors bad. Got the motor running better adjusted the tps sensor to 1.48 closed throttle 4.45 wide open. Shifts better but at 55 in do Convertor is unlocked. Isn't it suppose to lock in 3rd and forth? No flashing do light and the do off bitton works. What to do next? Maybe a temperature sensor thinking its cold and keeping it unlocked?

 

[79jasper]

Brake lights work?
For sure it's a E40D?

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[76ford466]

Yes it's a e4od. That's the only auto they had right that year? It's for sure not a c6 I have three of those and looks like my e4od from my 92 f350 gas truck. Will check the brake lights. It's a farm truck. Does it work off the same switch as the brake lights or a separate one on the pedal like the cruise which this one doesn't have.

 

[79jasper]

It would be just the under dash switch.
And yeah, I think could get c6 in '91.

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[trackspeeder]

This is an early gen E4OD. Like the later units it is supposed to lock in third and fourth gear. Don't depend on the OD off light to flash with this tranny. Scan it for codes before you go crazy.

There are many things that will keep the converter from locking. High or low fluid. Failed solenoid. Damaged seal or stuck valve. The converter itself could have a cracked piston or other internal damage.

 

[OLDBULL8]

It's an E4OD if it doesn't have a VRV on the IP and has a TPS, also the shift lever has a OD light on it. He said he set the TPS at 1.48 which is a little high, .99 to 1.1 is better set at. At 55, let off the throttle for a half second, should shift to lockup if it hasn't already, RPM should come down ~500 RPM. Normal shift to lockup is at 27 to 30 MPH with normal speed up, goes into OD at 37 to 41 MPH when let off the throttle for a half second, up/down.

If you pull the codes and get a 94 code, that is solenoid 3 clutch control, shorted or open circuit.. Clean the contact's on pass side connector.

 

[icanfixall]

Personally I think you have the tps set too high at 1.48 volts. Probably should check the wide open throttle setting voltage too. If it hit 5 volts the trans goes to limp home mode because the computer can't handle the 5.0 volts or higher. Reset to warmed up key on but engine off 1.2 volts. Maybe 1.25 but not any higher. Factory setting is .96 to 1.2 volts.

 

[icanfixall]

I recalled another isue to look for. If a stop lite bulb filament burns out and drops to the running lite filament you wont have any lockup. The computer sees the brake grounding circut and thinks you applied the brakes so it unlocks the converter. If it didn't you would kill the engine when you stop at a corner lite. I had this happen to me and was lost looking for the problem. Thought my trans crapped the bed. Pull on the flashers and check the tail lites. Your brake peddle has an interrupt switch that will make the converter unlock so you wont stall the engine when stopping. Just slightly apply the brake peddle and you will feel the converter unlock. Just keep some throttle on when doing this. These E4OD trans have a coast clutch too. Be driving at around 45 or 50 and let off the throttle. See the tach drop. Now add some throttle till you feel it lock up again and see the rpm come back up...