lumina is idling high

[angeleragon]

I took my car to the shop to see if they knew what was wrong and they dont evan know where to start. It started idling high but it dosent do it all the time, sometimes it will start when its been running awhile or the other way around, than after that started it started shifting funny,it shifts fine if your foot isnt on the gas but if it is you have to let up off of it fot it to shift, it also has been sucking up gas big time. The shop said that no transmission codes showed up so he dosent think its the trainy,theres also no engin light on either. If anyone has any idea let me know, I would like to get it fixed but dont know where to start cause I dont want to replace something does not need to be replaced.

[jeffcoslacker]

Sounds VERY much like a bad TPS...sorry, don't know how I missed your post this long...

Mine did the EXACT smae thing last year...it did it for a while, then went away...then came back with a vengance...same exact thing, sometimes it would idle at 40 mph...sometimes I'd have to give it gas then let off abruptly before it would upshift...other times it was fine...

the ECM has no way to tell that the TPS reading it's getting is false, so no code will be set as long as the signal is still within parameters (even though incorrect)

The only thing I could think of that had idle speed and tranny shift points involved was the TPS...changed it, and after a short drive to relearn idle speed, it was fine again...

The TPS is about $35, very easy to change...you'll need the proper size Torx driver bit...

The TPS tells the tranny to delay upshift if you are stepping into it hard...so if the signal from the TPS is wrong, it thinks you are hitting the gas harder than you are, so the tranny reacts accordingly, and the idle speed is messed up...

[jeffcoslacker]

Few problems on here I can tell people with any certainty exactly what's wrong...but this is a lock. I'm 98% sure a new TPS will fix you up.

Take the old one off and shake it....mine had a little rattle inside the new one didn't...bet yours will too...

[angeleragon]

thanks for the info,Ill try that and hope it works

[jeffcoslacker]

Good luck...just remember you'll have to drive it a bit (mine was for about 20 minutes or so, making several stops and starts) before it calms down and starts idling correctly again...it has to relearn with the new input..

[d12x12d]

Originally Posted by jeffcoslacker

Good luck...just remember you'll have to drive it a bit (mine was for about 20 minutes or so, making several stops and starts) before it calms down and starts idling correctly again...it has to relearn with the new input..

it should take about 100 miles for the computer to relearn its idle speed

[jeffcoslacker]

Originally Posted by d12x12d

it should take about 100 miles for the computer to relearn its idle speed

Naah...at the shop we used to just block the wheels and let them sit in drive with the emergency brake on...about 15 or 20 minutes and they were stabilized once again..

When I replaced my TPS, it took one trip over to the bait shop to get crickets for the Pacman frog and by the time I got home it was fine...only about 6 or 8 miles city with a lot of stop signs...

[angeleragon]

Thanks again it was the tps now its running like it should