s14 sr20det idle problem

[gp1300r]

here's the breakdown....s14 sr20det with a weird idling problem....
i believe the vtc sprocket is bad and i have another one to replace it, but haven't installed it yet. here's the problem....the idle was set to idle around 2,000 rpms to eliminate the vtc sprocket rattle. now on some days it'll idle at 2,000 rpms all day and on some days it'll idle at 2,000 then after i drive for about 10 minutes it'll drop to 1,100-1,200 rpms. what would cause it to drop like that?and why is it random? also what are things i should check? also if this matter's the previous owner used 5w30 synthetic oil. (just bought the car) i've searched and found nothing that resembles my problem.

[s15specR]

The ECU adjusts the idle once the car has warmed up. Therefore at different temps it will idle at diff. rpms.

[djcobra]

Replace the Sprocket first! Your car shouldn't idle that high at all, unless your running stupid aggressive cams; even then they don't idle that high.

s15speR is correct regarding the ECU adjusting idle at different temps.

Replacing the Sprocket shouldn't take you long just make sure READ the FSM.

Good Luck.

[gp1300r]

thanks for the replies. i just downloaded the FSM and it doesn't seem that hard to replace. thanks