AW4 help

I serched without success and I'm hoping some of you know what's up with my trans.
It could be that it's just worn out after 200k but it's a new trick after sitting for several months so I don't think so.
Accellerating from a stop, the trans shifts unusually fast up through the gears and stays in OD, no matter how hard I drive it. It will downshift manually but seems to slip on the downshifts. I retentioned the kickdown cable without change and the fluid has only about 5k on it and it's at or above the full mark. Any help would be greatly appreciated.

Post year/engine for best results. Any check engine light??

slowrider said:

the fluid has only about 5k on it and it's at or above the full mark. Any help would be greatly appreciated.

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transmission fluid expands a lot more than many fluids when it heats. It's probably not your problem right now, but once you get her working again, make sure the level is correct-- you can start aerating the fluid and cause damage if it's too full.

Thanks for any help, its an 87 MJ 4.0

birchlakeXJ said:

Post year/engine for best results. Any check engine light??

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Neutral start switch possibly, or possibly TPS. Those are the places I'd look first.

When my TPS was going intermittently bad the trans would do funny stuff, like not shift quite right, shift out of OD on the highway, torque converter lock and unlock, things like that.

It also gave me intermittent bad idle.

The TPS checked out fine, so did everything else. I decided it had to be the TPS and drove around for two days with the plug back-probed and a meter taped to the driver's wiper before it finally did it and confirmed that the TPS was bad.
The NSS can cause similar problems.

You should be able to unplug the transmission computer, this will give you a selection of gears, manually shifted. (forget which ones right off hand) If it shifts without any slipping, etc. with the ECT unplugged then the problem is probably electronic. If you still have slipping and so on with the ECT unplugged then it's likely internal to the transmission. (Keep in mind that you have to manually shift the trans with the ECT unplugged, it won't shift by itself.) It probably gives you a similar set of gears to an A340 with the ECT unplugged, as described in the Supra TSRM:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=AT&P=20

TPS.

Thanks, I'll throw the spare in and try it.

Make sure it's adjusted properly.

If the TPS doesnt do the trick you could have stuck valves in the valve body. My Trans shop is in Huntington Beach bring it by and I'll check it out no charge to members. Mike 714-412-9887 thats my cell or the shop 714-848-0066

This has some good diagnostic info. http://www.transonline.com/transdigest/magazines/1997-10/Shift%20Pointers/index.html

My bet is the TPS as well, as they do wear out.

If it is not the TPS, try unplugging the TCU and shifting manually. If it shifts Ok with the TCU unplugged, then your problem is electrical, if not, then it is mechanical.

XJSPEED said:

If the TPS doesnt do the trick you could have stuck valves in the valve body. My Trans shop is in Huntington Beach bring it by and I'll check it out no charge to members. Mike 714-412-9887 thats my cell or the shop 714-848-0066

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Thanks Mike, I haven't changed the TPS yet but thanks for your offer, I'll keep it in mind.