AW4 Problems after wheelin?

96XJ 4.0 AW4 auto

First thing, been having problems with the tranny since I drove it from Arizona to Kentucky about month ago. Sometimes when driving the RPM's will go way up and then after a bit it will be normal. Well, today was wheeling and after a long hard day got on the highway and found I only had 1/2 gears. No others, lets see if I can get this all out.
1. In "D" it would get up to about 25mph before the RPM's maxed and it wouldnt shift.
2. If I rev'd the engine I would lose all gears.
3. If I put it in "1/2" it would drop into 1st but wouldnt shift into 2nd.
4. If I put it back in "3" or "D" it would only go to 25mph.
5. Again if I rev'd the engine I would lose all gears until I dropped the selector back into "1/2"

I did get under there and checked everything. I did break the tranny mount earlier that day and the 4lo selector came out of the mount underneath. We strapped the tranny back down and it was fine after that. I did notice that the NSS was lose and adjusted that one way and the other way and it did nothing to solve above problem. Any suggestions? Throttle Postition Sensor? Crank Position Sensor? Tranny computer or just the tranny altogether? Thanks all Jeff CamoXJ

so are you still in mesa or are you in Kentucky if you are here I could look at it. If it is the tranny I can rebuild it for a better price than shops can.

Sounds like the throttle position sensor. On the auto it has two sections, one for the motor computer and a second for the tranny computer. Sounds like it is going intermittent. Have you pressure washed under the hood lately? That is the thing that most often kills the TPS, the second is cleaning the outside of the throttle body with carb cleaner.

AzXJman-moved to Ky about month ago. Wish I was still there I could use a new rebuild tranny )

Thats the second person that suggested the Throttle postion sensor, I had probs with it a long time ago but the engine didnt want to run at all, very rough. Right now the engine runs perfect, tranny just wont shift, could the TPS cause this? Reverse works like a charm. Thanks Jeff CamoXJ

After re-reading your problems it doesnt sound like the transmission it self. I would say tps.

it is the throttle position sensor.

It could also be that the NSS has lost one of it's contacts inside. There are 2, one of the neutral lockout & the other sends the signal to the TCU to tell it what gear range you're in.

I'd reset the TPS & adjust it to 4.0-4.4v output and then pull apart the NSS & clean/rebuild it.

If you said the NSS was loose, I wonder if you damaged it when the shift linkage got messed up as it's connected to the other end of the linkage shaft.

-jb

I'll check the NSS tomorrow, replaced the TPS and it did nothing. I was thinking of removing pan and checking for something loose inside the tranny but I'll do the NSS first. It was only loose on the small bolt where you adjust the NSS so maybe thats not it but check it anyways. Anything else. THanks Jeff CamoXJ

Checked the NSS and it looked like there was something going on inside there. Dont know if I'm missing a contact (not the deal w/spring side), there is some plastic missing where there might of been a contact, I'll have to try and find one to see or maybe one of you has one they can snap a pic of. Thanks Jeff CamoXJ

replaced the NSS and it didnt do any good. When you take off in drive you can get up to about 25mph, if you let off the gas and press it again you have to keep pressing gas pedal till it catches back up to the rpm's to get forward movement again (if that makes sense). I'm at a loss now, any more help would be appreciated. Jeff CamoXJ

Blown fuse to the TCU? I know on the earlier models there is a 7.5 amp (IIRC) fuse under the glovebox where the TCU is located that will blow if things get wet elsewhere, causing a short. Some of the symptoms described sound like this is a possibility.

I checked the fuses in the engine bay that go to the TCU but maybe there is one under the dash, I'll go check real quick. Jeff CamoXJ

giranger said:

replaced the NSS and it didnt do any good. When you take off in drive you can get up to about 25mph, if you let off the gas and press it again you have to keep pressing gas pedal till it catches back up to the rpm's to get forward movement again (if that makes sense). I'm at a loss now, any more help would be appreciated. Jeff CamoXJ

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Did you adjust it correctly? Sounds like you're stuck in 2nd gear & not shifting into drive at all.

-jb

pulled the TCU last night and took off the case and 1 resistor and 2 diodes were corroded to the point where they werent connected anymore. So I guess my incident in the pond about 6 mths ago wasnt good for it. I did take it apart after it happened and cleaned it really good with contact cleaner and allowed it to dry but I guess it still corroded anyways. So now I'm gonna see if I can find those parts at Radio Shack and see if that works. Thanks and I'll update everyone when I figure something out. Jeff CamoXJ

Why not grab another TCU at a junkyard?

I did and keep it as a spare...my wrecking yard just gave it to me.

Havent found any at a salvage yard yet, it has to be from a 96 also and its hard enough trying to find the exact year much less a free one ) Jeff CamoXJ