transmission problem

i have a 96 Taurus with a 3.o and auto tranny that wants to jump from 2ND to first on certain occasions,. It happens when i hit any kind of grade when i'm going at a speed where the tranny is in second. I changed the fluid and filter, and the speed sensor. I'm thinking it could be the MAP sensor(if that's what its called on a Taurus) or the throttle position switch,or the range selector switch? there are no codes also. Any help would be great. thanks. Its like the computer is getting wrong info about the load conditions,and telling the tranny to shift down .

i went ahead and tested the tps(throttle position switch) which i think gives info for proper shifting, it might replace the kick down cable thats on older cars. Anyway i back probed the switch with the key on and as i opened the throttle the voltage went up slowly to close to 5 volts as it should. i did notice a spike or open circuit at 1.9 -2.0 volts. it only does it at that position every time i tested it. so if there is a flat spot in the sensor then it might be the cause of the tranny kicking into 1st gear. the tps is only 36 bucks ,so in guess ill put another one in tomorrow. and from what i can tell there is no adjustment when installing it ,so just 2 screws and its done! i have to say the speed sensor was a lot harder to get to. there are a few more sensors that talk to the computer that effect shifting but i havnt done much research on them yet.

it wasnt the tps ,so now i dont know what else to check! help.......

Does the car idle fine and run fine when not on hills? Do you have access to a scan tool with a datastream mode so you can monitor calculated engine loads and such? When's the last time the car had a tune up?

-Rod

May God help us all. My 94 Gl Wagon 3.0 has a mind of it's own. It slips on upgrades if you get off the gas but don't come to a complete stop. It feels as if it is holding back or not wanting to go into overdrive when you are driving. At highway speeds it eventually goes into over drive though. It has a harsh shift from 1st to 2nd. I can also hear a sucking sound coming from the driver side of the trans. This can only be heard when you first crank it up in the morning. Also upon first starting it in the morning it will idle down real low to the point of cutting off and then the idle will return to normal. The cruise control works well. I recently changed the pan and filter on the trans. I'm stuck. I'm thinking aboout changing out the "range sensor". I'm just not sure what all that proceedure consists of. Maybe a shift kit or a diffrent stall would help these cars?:banghead:

Does the car idle fine and run fine when not on hills? Do you have access to a scan tool with a datastream mode so you can monitor calculated engine loads and such? When's the last time the car had a tune up?

-Rod i just did a head gasket job and timming set, the engine runs like new. i had amco do a test on it and there were no codes, they think its internal, but they wanted $400 just to go any farther. so im selling the car. i do have a 93 taurus with a bad 3.8 motor and a good tranny. i dont know if that tranny would work as a swap. and without a lift i think it would be tuff to do.

May God help us all. My 94 Gl Wagon 3.0 has a mind of it's own. It slips on upgrades if you get off the gas but don't come to a complete stop. It feels as if it is holding back or not wanting to go into overdrive when you are driving. At highway speeds it eventually goes into over drive though. It has a harsh shift from 1st to 2nd. I can also hear a sucking sound coming from the driver side of the trans. This can only be heard when you first crank it up in the morning. Also upon first starting it in the morning it will idle down real low to the point of cutting off and then the idle will return to normal. The cruise control works well. I recently changed the pan and filter on the trans. I'm stuck. I'm thinking aboout changing out the "range sensor". I'm just not sure what all that proceedure consists of. Maybe a shift kit or a diffrent stall would help these cars?:banghead:
when you changed the oil was it burnt, and was there black stuff coating the pan? or a lot of metal flakes. if so its probably shot. Like mine

Actually the fluid was in great shape I had done 2 flushes prior. There was a slight amount of black coating in the pan. Nothing out of the ordinary though.

Actually the fluid was in great shape I had done 2 flushes prior. There was a slight amount of black coating in the pan. Nothing out of the ordinary though.


i would check the engine codes before i replaced any thing. you can use the check engine light to get them. here is a link to peek at for transmission info that might be helpfull.
http://www.aa1car.com/library/transmission_ford_ax4s.htm

this is a good one for getting codes on the earlier cars:

http://www.jeepforum.com/wiki/index.php/OBDI_Error/Check_Engine_Codes

i would check the engine codes before i replaced any thing. you can use the check engine light to get them. here is a link to peek at for transmission info that might be helpfull.
http://www.aa1car.com/library/transmission_ford_ax4s.htm

this is a good one for getting codes on the earlier cars:

http://www.jeepforum.com/wiki/index.php/OBDI_Error/Check_Engine_Codes


sorry i gave you a link to jeeps! ill try to find the right one