Redrek43

ive searched and searched and have yet to find an answer but what is the stock idle supposed to be on an sc400? in park she idles anywhere from 800-1000 and in drive anywhere from 400-600 rpms. i just changed plugs and cleaned the iacv recently(lots of junk) as i was having an idle issue once the car was warmed up. doing the ignition coils soon and i know how to adjust the idle via the throttle cable or tps but i guess im at a loss as to what the rpms should be at. car runs extremly better after the iacv cleaning, seafoam, oil change and then the plugs and wires(all in that order lol). its a 92 lexus sc400, miles are 198300 and other than the new idles issues she has ran perfectly. any help would rock oh and when i first got the car the idle was 1000 rpms parked and 7-800 in drive

chiken

Check your tps. I just adjusted mine for the same problem and it fixed it. Ill have to look up the pins on the dlc connector but you you want it adjusted for 0 volts at closed throttle and progressivly climbing in voltage with throttle applied. Im at work atm and will try to get you the pins in the next day or two( i have school all day tomorrow and work tomorrow night) so the only thing ill be doing at home is sleeping tomorrow.

durps

iTrader: (8)

Mine is at 700rpm in park after fully warming up. In drive the same as yours.
Check and do the 12v fuel pump mod to see if that helps your problems, or replace your fuel filter. Tps might be the issue too.

Redrek43

ok ill try both! thanks!!

chiken

Just real quick before I head to work, I found the TPS inspection that I used in the FSM. Check the voltage with key on engine off at the TT terminal on the DLC and body ground. (Don't touch the brake pedal during this process or it will give no voltage readings) At closed throttle, you should have a voltage of near 0 volts. The voltage should gradually increase as you depress the pedal.

Mine was reading 1 volt at closed throttle which is why my idle was high, once I set the TPS to 0 volts at closed throttle it went down to around 650 or 700.

SC400slide

iTrader: (11)

Mine idles at 1500 rpms when cold, 1200 in drive, and about 700 in reverse...very interesting. I suggest looking into setting your TPS to spec if you haven't already.
GL!

(sorry for any typos, the iPad keyboard is slightly small... )

chiken

Any updates?