vham62

92 Lexus sc400 When first starts runs fine but high idle around 1200 rpm. As soon as it starts to warm up then idle continually up and down between 1200 and 1800 rpm. Took out and cleaned the IACV. While idle is going up and down can unplug IACV and NO difference also can unplug the TPS (farthest away from the block) and NO difference. But while it is acting up unplug the TPS (closest to the block) and just goes back to 1200 rpm and stays steady. Is this TPS my problem? Don't want to buy one if its not. And why is it now running so high on rpm's. NOTHING has been adjusted was running great before this problem! NEED ADVICE FROM SOMEONE WHO KNOWS!!!!

account2x

iTrader: (5)

if you have 2 tps, one is for traction control

vham62

I am already aware of that

93MSB

iTrader: (8)

have you looked over all the vacuum hoses for cracks etc?

vham62

Yes NO vacuum leaks

vham62

Can anyone help with this problem??

vham62

Any more Ideas before I go buy a new TPS?

93MSB

iTrader: (8)

heres the factory service manual, d/l it and follow the diagnosis steps

right click - save as
http://www.driftshop.com.au/SC300%20Manual.pdf