trans issues - Page 2

1986nate · #16 10-02-2010, 06:28 PM

Quote:

Originally Posted by jjanak79

what its doing is . i'm going 75 miles an hour. I'm running under 2500 rpms. all of a sudden it shifts up and (it feels like its slipping.) goes into 4th like over 2500 rpms. and then settles down under 2500rpms. is that better?

I understood that from your first post. Still seems like a TPS issue causing it to lock and unlock based upon getting improper readings on throttle position.

oab_au · #17 10-02-2010, 07:10 PM

Yes the TPS can be a cause of the, torque converter unlocking and locking up again. The vibration of the throttle shaft, causes the TPS wiper to etch the carbon tract, to form a bad spot. This usually is at the throttle position that, the car usually cruises at.

The Overdrive term is just that, to drive over the 1:1 ratio.
As Dave says the gearbox gearing is higher/over 1:1, so our 4th is an overdrive ratio, as 3rd gear is 1:1.
This really does not mean as much to-day as it did when we had 3 speeds and a add on box, to provide an OD ratio. Now most boxes have 4th gear at an overdrive ratio.

Locking the converter, is more about economy than raising the ratio, as it can lock in other gears too.

Harvey.

jjanak79 · #18 10-03-2010, 10:34 PM

so replace the TPS

Hocrest · #19 10-04-2010, 04:38 AM

Quote:

Originally Posted by jjanak79

so replace the TPS

Have you checked it yet?

dcarrb · #20 10-04-2010, 06:10 AM

Quote:

Originally Posted by jjanak79

but a tps sensor is 254 bucks at my parts store in my town!

$169.99 + tax/shipping at Autozone's online store.

As others have suggested, try cleaning/adjusting first.

My TPS "bad spot" was 50-55 MPH in 4 the gear. 75 strikes me as a bit high for a typical throttle position.

dcb

amber · #21 10-04-2010, 06:25 PM

Quote:

Originally Posted by dcarrb

$169.99 + tax/shipping at Autozone's online store.

As others have suggested, try cleaning/adjusting first.

My TPS "bad spot" was 50-55 MPH in 4 the gear. 75 strikes me as a bit high for a typical throttle position.

dcb

That figures, the TPS has conductive plastic elements and certainly no carbon is involved. A deposit on the element is very likely so cleaning is well worth a try. The difficulty is to get a cleaner in to the works without breaking things to bits.

jjanak79 · #22 10-07-2010, 07:59 PM

ok i bought a new tps from auto zone and its giving me the same crazy readings and it has dead spots in the same place as the old one