Transmission Shift Issues?

[Markb873]

I have a 2000 Kia Sportage. The transmission will not shift into into fourth gear independently of locking the torque converter when cold. This is only a problem when i get on the highway quickly. I have to drive under 60 because the engine is spinning at 5000 RPM before warm.

After warm it likes to lock the converter and shift to fourth at the same time but I can ride the brake and gas to make the converter unlock. If I floor it up to speed it will lock the converter in third, wait, and then shift to fourth normally.

Any help would be appreciated. I'm sick of getting better gas mileage on my V6 SUV that is 7 years older. So every little bit helps.

-Mark

[LMP]

4th gear indeed will NOT engage until engine temp is up to 140degrees F. THIs is built-in the computer....only way you can bypass this is to intall a resistor bypass to the engine temp sensor i order to fool the computer thinking the engine is warmer than it is actually...
..and by the way, my 93 Pontiac Transport V6 3800 gets better gas mileage than my Sporty....

[Markb873]

Ahh, amazing when you put two and two together. I had swapped out PCMs due to over advanced timing. Old one must have been tweaked possibly? I think it may had developed around then. I used to drive 25 mph for a bit of a distance when cold so I never really noticed.

Thanks for the insight.

-Mark

btw My Chevy L35 Vortec 4300 gets 22 Highway. I drive it to only get about 12 city though.

I was Kinda Bummed because I had a 1998cc four cylinder in an Escort. same size at the Mazda built Kia. I knew the "Sporty" was heavier and didn't have VCT but I never thought gas mileage would be cut in half literally. Live and learn i guess.