View Full Version : Help needed. Car won't downshift


krunk99cam
10-14-2009, 07:53 PM
I have a 99 z28 a4. It won't downshift at WOT anymore and I don't know what would cause it. Any help would be greatly appreciated.

krunk99cam
10-16-2009, 09:42 AM
Anyone?

2001slppewterss
10-16-2009, 01:12 PM
my car is doing the same thing I think.....it runs pretty good from a dead stop, but from a rolling punch it's really weak....also cruising 50-70 in overdrive, when you punch it, it accelarates very slow and doesn't downshift.....

I just got a new engine installed in my car(stock LS1 from the dealer)...and ever since then I've had problems with this....I replaced the TPS and the MAF(both with stock ac delco parts), did have an slp maf....cuz people suggested it was either the throttle position sensor or the maf.....those parts got the car closer to driving right, but now I've got a code for a drivers side pre-cat oxygen sensor and it's getting worse....I'm fixing to replace the o2 and hopefully that fixes it. Do you have any check engine codes??

maybe try cleaning your maf and if you can get your maf and tps tested.....

krunk99cam
10-16-2009, 01:32 PM
Yeah that's pretty much exactly what mine is doing.

I replaced the tps and the front o2 sensors but it still doesn't downshift. I haven't tried cleaning the maf yet. The only thing I know is that it ran perfect and downshifted before I got my headers installed but after that it hasn't downshifted right since.

jh2586
10-16-2009, 11:20 PM
check the adjustment on your tv cable and check the cleanlines of your throttble body.. sometimes when it gets gunked up it may cause that..

otherwise try flushing out your tranny fluid

JoshuaGrooms83
09-14-2013, 12:55 PM
ive been noticing this as well all of a sudden lately. anyone have any insight into this?

RPM WS6
09-14-2013, 02:49 PM
check the adjustment on your tv cable and check the cleanlines of your throttble body.. sometimes when it gets gunked up it may cause that..

otherwise try flushing out your tranny fluid

No T.V. cable on the 4L60E. It's an electronic trans; shifts (up and down) are PCM commanded, and line pressure is PWM. No detent/kick down cable, no T.V. cable.