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Slow 1-2 upshift when cold


NAXJA Forum User
First thing in the morning my 95 dosent want to shift into 2nd for probably a half mile, once it shifts it goes through the rest of the gears just fine and all gears fine for the rest of the day. It did this most of the winter and stopped when it got warm. About a week after I changed the fluid and filter it has started doing it again. Sticky solenoid? Just getting shot from miles and abuse? It has probably 180-200k on it, 85k on the mail route.
Two good suspects already posted, another one would be a crappy Chinese Throttle Position Sensor.
TV cable has been adjusted not too long ago, of it was that I feel like it would not shift correctly all the time. It has never had +4 fluid put in it. Same problem persists equally before and after fluid change. I've had several tps go out and it definitely dosent act like that, test out good with analog meter anyway.
Mine does this as well... and has for years. 100% temperature dependant. I am curious if it is something internal to the trans causing my issues. I tend not to cast though as it has approx 400k miles on it though lol

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It may just be an age and wear thing. All I have to add is that it's 01 trans so I had to splice the wiring, im pretty sure I soldered and sealed the connections, but I need to check them for corrosion. I need to check the grounds too.
My 96 holds first gear longer when first driven too, when cold. It has under 70k miles so I don't think it's wear related.

I've installed a Magnefine trans filter, so we'll see if that has any effect next winter. I also run Lubegard Red in it.
I probably attest to many small issues to age and wear, but my Ole jeep has been put out to dry for years if you know what I mean.... the o2 harness was ripped out at 180k miles and 13 years ago... it was my first car so it was held to the floor daily.... I laid tile and stone for 10 years using it as a tow pig for 1 to 2 tons of masonry on a trailer very often.... and now it's under geared on 35s with I'm assuming 400k miles.... the trans pump screams occasionally, it shifts funny occasionally... and I'm just glad it still goes 🤣

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Well, it seems to be getting worse, almost every time I shut it down it has an issue with that first 1-2 up shift, then shifts normally from then on out. I have an extra aw4 waiting to go in when this one finally gives up, so when it does I'm going to try and triage this one to figure out the failure, but im not hopeful, unless it's painfully obvious. On a side note. What about the map sensor? Could it be an issue here? the best way I can get it to do that first shift is to run it up to about 3k and fully let off the gas then it usually pops into gear.
This happens even if you simply turn off the key and immediately restart it, or does it have to be "cold" for that first shift to be rough?

I'm wondering if maybe the TCU is having some issue on power-up that clears after the first 1-2 shift. You said you had a space trans on standby, do you have a spare TCU (preferably a known good one) that you could try swapping in?
Immediate re start and go like a package delivery it will still shift okay, 5 or 10 minute cool down is when it wants to act up again. I do not have another tcu, just kept the good tranny when I junked my 01. I don't even know where the tcu is actually.