[Taranabas]

Hello everyone, I'm hoping to get some idea here as I am running out of patience with this project.

What I'm dealing with is a powertrain from a 94 F250 IDI factory turbo, E4OD. I've actually got it swapped into a 2009 Dodge, which has been a lot of fun. What is not fun, is getting this transmission to behave. The donor truck had been parked for several years, so I do not know the history on it at all. I rebuilt the engine completely, and it's running great.

Once I got the EEC IV all wired up and fresh fluid in the trans, I took it for a spin. It was a bit iffy at first, slipping in 2nd. The next day I drove it again and 1st/2nd felt good, 3rd was slippy. The next day I drove it everything felt great. I drove it to town a couple times. The next day I drove it to work, and on my way home I couldn't get it over 40-50KPH on the highway (I'm assuming that was 3rd. Any amount of throttle to accelerate and it would slip. I then rebuilt the trans myself. I found the drive clutch and direct clutch to be black and heated, but still lots of friction material left. The only other problem I found was one of the center support bolt/passages was quite loose, I backed it out with my fingers. (I'm aware the torque spec for these is only 10lbs) I also installed a transgo shift kit. (not the tugger). Also put a new MLPS on it.

I took the truck for a good boot the other day, and it felt pretty good. Decent shifts, the only thing I noticed was kickdowns didn't really make it want to downshift. I stopped to visit a friend for an hour, then drove home, and halfway there it started slipping like crazy again at about 100KPH, which I'm assuming was 4th. Today I checked the FIPL and it was 1.2 - 3.8V. I had a new one, so I installed it and set it to 1.4 - 4.1V.

I intend to put a gauge on to watch the line pressure before I drive it again, I really don't want to smoke the new clutches. Oh, and I pulled the codes and all I have are:
22 - Baro out of range
23 - Throttle sensor out of range (this is why I changed and calibrated the sensor)

Anyway, does anyone have any suggestions on what to attack next? I understand the TPS is really critical, and dictates line pressure, but is it possible for it to cause a slip? I have not replaced the solenoid pack, but I'm thinking that might be my next go.

 

[Mark Kovalsky]

Code 23 happens if you didn't hold pedal to the floor while the self test was running.

Do you have the engine speed signal and vehicle speed signals connected to the PCM? It needs both of those.

 

[Taranabas]

I definitely have the engine speed and vehicle speed wired in. Im getting VSS from a Hall effect on the rear diff, converting to the correct (forget what that was offhand) pulses per mile with a Dakota digital SGI-100BT for the PCM. The VSS must be working okay because it does shift at reasonable speeds, is that a safe assumption?

When is the self test routine performed?

 

[Mark Kovalsky]

Self test is performed when you read the codes.

 

[Taranabas]

So what's my next step? Should I order a solenoid pack?

 

[Mark Kovalsky]

Go to www.troublecodes.net/ford. Run key on engine off and key on engine on self tests and see what codes show up.

 

[Taranabas]

So to update on this, I tested line pressures and this is what I got. My shifter linkage doesn't reach 1st at the moment:
Low Idle | Stall
P - 90psi
R - 125psi | 325psi
N - 80psi
D - 82psi | 200psi
2 - 80psi | 200psi

I took the truck for a drive, and I get different results on different attempts. It's always good in 1st and 2nd. Sometimes it slips immediately in 3rd, sometimes it holds for a bit, then slips, sometimes it makes it to 4th and slips there. I can just be cruising along at 100kph and suddenly it will slip. I always back off the throttle immediately. I pulled codes again and i got:
22 MAP (vacuum) or BARO signal out of range
23 Throttle sensor out of range or throttle set too high
74 Brake On Off (BOO) signal open or short to ground (This is expected, I haven't connected this yet)
65 Check intermittent HO2S (signal or ground)
(R) E4OD truck - cycle OD cancel switch after engine ID is received
1984 3.8L ONLY - O, M Battery voltage high (check for electrical system overcharging)

The behavior of this trans is identical to what it was BEFORE I rebuilt it. What on earth is going on here!?

 

[Taranabas]

Oh, and I did not floor the thing when I pulled those codes, so I presume that's why the #23 again.

 

[Mark Kovalsky]

I hate replacing parts without a good diagnosis, but sometimes it's the only way. Replace the MLPS (Manual Lever Position Sensor,) sometimes known as the TRS (Transmission Range Sensor.) It is the sensor on the driver's side of the trans with the wiring harness attached.

When this sensor begins to fail it indicates that you have moved the shift lever to N when in reality it hasn't moved. The PCM doesn't know this, all it has is what the sensor tells it. So it obediently sets the trans to neutral. This seems to fit what you're seeing.

 

[Taranabas]

Well, unfortunately I have already replaced the MLPS with the updated one, and the new connector. I had checked the resistance values on the old one (when I had the same symptoms) and they were within spec, but I haven't done that on this one, I just set it via the indicator line on the housing. I will test the resistance values to verify my adjustment. One thing that I suppose is a possibility, is that my speed converter is putting out a signal that the EEC doesn't like, or gets noisy at high speeds. Would a sudden loss of speed input cause this? I would think it would set a code for that though.

 

[Taranabas]

And to be clear, by speed converter, I mean the Dakota Digital SGI-100BT that is converting my diff speed into the 8000 pulses per mile that I understand the EEC is looking for.

 

[Mark Kovalsky]

The resistance on the MLPS will be fine.

The speed signal could very well be your issue. If it drops enough it will cause the trans to downshift, which will feel like nuetral.

 

[Taranabas]

So to update on this, I pulled the PSOM out of the parts truck, and injected a square wave into it, and measured the output with a scope. I then did the same with the Dakota Digital SGI-100BT. The output signals at all speeds are very clean and crisp with little noise on both, however - the voltage is quite a bit higher out of the SGI. The PSOM outputs 10 Vpp (+/- 5VDC) and the SGI puts out 13.8 Vpp.
I then scabbed the PSOM into the system in place of the SGI, and put it where I could see the speedometer. Preliminary tests are good. I drove to town and back, and it didn't hiccup even once. Rock solid.
I hope this is the end of my troubles, knock on wood, but I will report back in a few days once I've driven it some more.

Now that it wasn't 'slipping' I found out it's totally gutless at ~120km/h, so I think I have some timing adjustments to fiddle with.