Needing advise on transmission...

[DOHC 281]

I have a problem with my everyday driver. Since we have at least two really good techies in our fold, I'm putting this on the forum.

The car: A 2000 silver Sable with a 3.0 vulcan and three speed plus OD tranny. Herc the Merc has 86,500 miles. I doubt if the tranny filter was ever changed. Fluids are topped off, clean and no odor. [The Miller Park parking lot AX special :p ]

The problem: 85% of the time, the tranny shifts smooth and quietly. Sometimes, the tranny will not engage between the 2nd and 3rd gear. Just like when you miss a gear with a manual transmission. [OK - it happened once, or more.] The revs go up and it won't shift until I "breath" the accelerator. Then it shifts. It seems to do it only when it is warm, and under load. At first, I assumed it was the transmission - typical for this model. After reading of a similar problem on the FTE site, I got the idea that it might be the throttle positioning sensor (TPS). After all, the check engine light did come on a few months ago when this problem started. Never saw it since, however.

The solution: Should I just go out and purchase a genuine Ford TPS and hope for a "fix"?

:confused:

[animal]

YOu could just put a multimeter on the tps and drive around. I believe it tops out at 5v. Or maybe someone has an autotap you could borrow. It should be able to tell you the tps voltage and tps open % as read by the computer. Since the tranny is probably computer controlled, maybe there's some weird short or faulty wire on the way to the computer.

it'd at least rule for or rule out your thought on the tps.

Maybe it's just time for another svt :D

[CSCOBRA]

I would not just replace the tps, if the tps was bad it should effect all shifts. If you could run a ecc test to check for codes it would help. It probably is more likely a range sensor or speed sensor or a internal problem.Is the fluid smell burnt?

[DOHC 281]

Looks like I'll go for a check on codes. Thanks for the advise guys!