Down shifting at intermittent times

[cryodenk]

I have a 94 GT Mustang, which is downshifting when at cursing speed with constant accelerator pressure. Any ideas on what would cause this?

Papa Marine

 

[94TURBO5 O]

I take it this is an auto right?

 

[EpiKk3]

yeah im guessing its auto..
i dont know what your cruising speed is so that could be part of it.. but with my old z24 [auto] every time i was set at about 40mph it kept shifting up and down .. got kinda annoying actually i guess its just the set place for the autos to shift

 

[Bigsho2020]

I had the exact same problem shifting in and out of overdrive while I was on the highway. I had to have my tranny re-built. They said it smoked the overdrive belt.

 

[Chronos[AsG]]

Mine was doing that years ago. A 94 GT, too. I took it in to the dealership and they said they had to replace some chip or something that was messed up. Its been so long that I forgot exactly what it was, but you should have it looked at ASAP. If I remember correctly it cost like $250 to replace the chip. Much cheaper than a new/rebuilt tranny.

 

[cryodenk]

yes it is a auto and it is doing this at speeds 40-55 it feels like it is going form 4 down to 2 but i am guessing it is going into 3rd. i have taken to 5 shops and it is so intramentent that they can not figure it out. they have hooked it too the comp and it says nothing. so please any help would be great do not want to wait for it to fry the tranny

 

[Chronos[AsG]]

I didn't have time to today because of work, but on Monday I will call the dealership first thing and see if they still have a record of what they did to my car to fix it. Hopefully that will help. I'll post here as soon as I get an answer.

 

[Green 94 5.0]

it sounds like either your mlps is bad, or you trashed the OD band.

 

[bjl95mustang]

Maybe the wiring in the pan Is loose? If the wires are loose it could cause it to shift 2 second at random.

 

[Chronos[AsG]]

Well I called the dealership today and their records in the computer dont go back that far. Sorry I couldnt get anything specific but I would definitely take it by a dealer as soon as you can.

 

[phatboysh]

My art carr tranny did this, I had the same symptoms as you and everything. I rented a rather large diagnostics tool from a ford dealer, which showed me that the computer thought the car was in O/D while the transmission went on its own business downshifting and upshifting, staying in O/D most of the time... tires screeched one day on the freeway on a 4-3 downshift. Called up art carr, they were clueless, and they sent me another valve body. Problem fixed.