E4OD High RPM Shift Between 1-2

[Grumbles]

So... another E4OD thread. I've been fighting with this transmission for weeks and after diagnosing and replacing a bad shift solenoid pack, the transmission stubbornly will not shift from 1-2 at anything less than around 2700 RPM.

I did as an experiment adjust the FIPL down from 1.2v at idle to .9v and that didn't seem to change the shift point.

First question: Is a shift point that high normal? When I manually shift into 2nd, it will shift and hold the gear well below the 2700 RPM shift point that Drive does. Other than the high shift point, the shift is firm but not harsh and holds the gear fine as long as you stay at appropriate speed and rpm. Transmission will shift through the rest of the gears smoothly and winds up at a little under 2500 RPM at 60mph in overdrive. (4.10 rear)

Second question: Only code I have is a code 22, which is barometric pressure sensor voltage out of value. I purchased a Motorcraft DY-527 and installed that. Initially when I did a KOEO test, that cleared the 22. After doing a 10 minute or so drive, turning the truck off and repeating the KOEO, code came back. Is a DY-527 the correct Baro sensor? The old sensor was giving me anywhere between 450-550 hertz when I checked it with a meter at idle. I'm nearly at sea level, so I'm pretty sure it's bad.

Third question: Assuming the new baro sensor is good, is there any test I can do of the PCM other than visual inspection? I know the signal wire from the baro sensor goes directly to the PCM, so if you have a code 22 that doesn't go away potentially the PCM is bad.

 

[nelstomlinson]

following

 

[Nero]

I assume you checked fluid level? Because that sounds like low level to me.... Or low rail pressure.

 

[Grumbles]

I assume you checked fluid level? Because that sounds like low level to me.... Or low rail pressure.

transmission is full with engine warmed up and turned on. I did notice a stretch of rubber hose with about 6 hose clamps on it near the transmission pan...

 

[Nero]

If it's a cooler line, it could be a fluid restriction.

 

[Grumbles]

If it's a cooler line, it could be a fluid restriction.

Tomorrow I'll investigate the rubber line and see what it turns out to be. I'm also going to drop the pan and address a leaking gasket that I just installed when I dropped the pan before to install the new shift solenoid pack. I suspect the pan is warped and that I'll need to bend it back into position. After getting all of that done I'll report back.

 

[Cant Write]

Transmission will shift through the rest of the gears smoothly and winds up at a little under 2500 RPM at 60mph in overdrive. (4.10 rear)

This seems off to me. My ‘92 van doesn’t have a tach. But using an online calculator (crawlpedia.com) at 60 mph in OD with my 4.10 rear and factory sized 30” rubber gives me 1929 rpm.

Does your tach show 2500 rpm? Or how are you coming up with that number?

Doing the calculation in direct (1:1) gives 2700 with 30” tires and 2580 with 32” rubber.

I’m following along as I’m no expert. But are you sure you are shifting into OD? Or maybe the tach reading is wrong...?

 

[Grumbles]

This seems off to me. My ‘92 van doesn’t have a tach. But using an online calculator (crawlpedia.com) at 60 mph in OD with my 4.10 rear and factory sized 30” rubber gives me 1929 rpm.

Does your tach show 2500 rpm? Or how are you coming up with that number?

Doing the calculation in direct (1:1) gives 2700 with 30” tires and 2580 with 32” rubber.

I’m following along as I’m no expert. But are you sure you are shifting into OD? Or maybe the tach reading is wrong...?

It's possible I miscounted the shifts and I can check that today. I had to finish rebuilding the rear brakes before I could do test drives again. The tires on this one are stock, whatever size that is. I have tested the RPM sensor that goes into the injection pump and it checks out fine when resistance tested.

Another thing I can test is if the OD button does actually turn off OD when I press it. I haven't tested that either.

 

[Grumbles]

It's possible I miscounted the shifts and I can check that today. I had to finish rebuilding the rear brakes before I could do test drives again. The tires on this one are stock, whatever size that is. I have tested the RPM sensor that goes into the injection pump and it checks out fine when resistance tested.

Another thing I can test is if the OD button does actually turn off OD when I press it. I haven't tested that either.

Okey dokey, updates. I dug into the mess of hose clamps on the cooler line and found that the cooler line had been cut at some point. My theory is the hose clamps were placed to add support to the rubber replacement line to keep it from blowing. I replaced the old line with a piece of transmission cooler rubber line rated to 400psi, so problem solved there.

Just finished the test drive. Unfortunately the shift point did not change after replacing the line, but I was able to verify a few other things:

1. I am grabbing all four gears. Counted them out as I sped up to 60mph.
2. Overdrive cancel switch does work. Dropped me out of overdrive in to 3rd and then back into overdrive without issue.
3. With the tires and rear end I have, I do hit about 2400rpm when in overdrive cruising at 60mph. I have checked the speedometer against a GPS one and its around 3mph off, so the usual.
4. I still remember how to rebuild drum brakes. Pedal didn't hit the floor today when braking. Yay.

I am going to check my metal tag on the diff case to double triple check that I do indeed have a 4.10 rear and not something higher. One other thing I noted when doing various research today is that I can use an 89-91 transmission. Apparently something changed enough in 1992 that it's not a bolt in replacement for my setup.

Next steps I'm thinking about are doing another KOEO test to verify the code 22 is staying away and pulling and visually inspecting the PCM to make sure the magic smoke hasn't been let out. I'm also going to pull/clean/inspect the VSS to make sure nothing funny is going on there.

Thoughts?

 

[Nero]

Well dang, shame it's not as easy as the line, but now you don't have to worry about it popping and leaving you stranded.

Did this issue occur before replacing the solenoid pack? It almost sounds like the 1-2 upshift spool may be sticking too.

 

[Grumbles]

Well dang, shame it's not as easy as the line, but now you don't have to worry about it popping and leaving you stranded.

Did this issue occur before replacing the solenoid pack? It almost sounds like the 1-2 upshift spool may be sticking too.

Thinking back, it did. It was shifting rougher when I first got it running again, so I stopped test driving and started researching what caused weird transmission things... which led me to the shift solenoid pack and it's connector... which led me to finding the connector o-ring had failed and atf was getting all over everything. Replacing the shift pack and the connector fixed all the solenoid codes, bringing us to today basically. I have replaced the MPLS on a long shot but that didn't change behavior. Someone had changed it before me though as it already had the '95+ connector on it.

FIPL was replaced and tuned as well. I've cleaned up every ground in the engine bay that I can find and I cleaned the common ground for everything under the bed. The trailer wiring that I pulled out was... sad.

No burned out tail lights and the brake lights are fine as well. I did have to replace the external voltage regulator on the alternator to get the system charging again but I haven't load tested the alternator in particular to see if it's getting tired.

Volt gauge doesn't read at all currently in the instrument cluster but from my understanding that happens on this truck and the individual gauge needs to be changed. All other gauges work so I don't think it's a common ground issue.

 

[Grumbles]

Moar updates. I checked out the VSS today. It looked good, didn't have much schmoo on it. I ohm'd it out and it showed ~1800 ohms, right in the butter zone for the sensor, so I believe it to be good. Next up will be doing that KOEO test again and the PCM inspection. I didn't have time today.

 

[Greenie]

I've used fuel injection line clamps on the cooler lines. The stainless steel worm drive clamps allow rubber to creep through the gear cutouts which eventually loosen their grip. I've never noticed much pressure in the cooler lines but I did have ongoing drips with the old style clamps.

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[Grumbles]

I've used fuel injection line clamps on the cooler lines. The stainless steel worm drive clamps allow rubber to creep through the gear cutouts which eventually loosen their grip. I've never noticed much pressure in the cooler lines but I did have ongoing drips with the old style clamps.

You must be registered for see images attach

I think I read somewhere that the cooler line will experience ~20lbs of pressure so I don't think all the clamps were needed. I bought the line and currently am using two clamps, one at each end. I did cut the line a bit long so that there's a good amount of hose over metal cooler line at either end. No leaks from there. However, there is a corner of my transmission pan that is bent slightly and despite my best efforts I couldn't get it true. I've managed to slow it down to a few drops per day, but quite annoying. I'm going to have to buy the really nice formed gasket and/or a new pan (preferably with drain bolt) to fix the problem for good. That will be another day's repair though. I realllly want to figure out why I have the high 1-2 shift.

 

[Rdnck84_03]

Can you get it to shift sooner if you quickly let go of the throttle after a fairly aggressive acceleration?

James