car idles... and when i turn it on it stays at 3ooo rpm.. used to be like at 1500 rpm

 

Have you checked anything out so far? Any recent modifications that might help us pinpoint a problem?

You could start with checking the TPS voltage.

 

it's a single cam turbo d16z6. i changed the manifold. because mine was cracked. but its still an si manifold. just like the stock.

 

where is the TPS voltage. how do i check it?

 

where is the tps voltage. (its a d16z6 turbo.)

 

Which manifold? Intake or exhaust?

The TPS is on the throttle body (the sensor is usually on the left side of it).

If it was the intake manifold, you may have messed with the TPS and throttle body when changing it.

Just use a voltmeter to test the wiring for the idle and WOT (Wide Open Throttle). WOT should be around 4.5v I believe and idle should be around 0.45 to 0.49 to be within spec.

If you do not have a voltmeter... invest in one. Good one can be had for less than 20 bucks.