Idle Problem

[99EclipseRs99]

Hi everyone, I have a problem with my idle surging to about 3500 rpm at startup then staying elevated between 1500 and 2000 rpm thereafter. It all started when I bored an extra throttle body I had to 52mm so I could use the stock butterfly plate. I bored it a little too far and the butterfly plate wouldn't seat properly. I installed it anyway and the engine started to sputter. I then gave up on my new and messed up throttle body and decided to put my stock throttle body back on. Now I'm idling high and surging at startup. I searched and found that it could be a vacum leak or my throttle cable is a bit off. I would appreciate it if anyone could tell me how to check for these ailments or if it is something else.
Thanks,
Ryan

 

[VelocitàPaola]

To check for vacuum leaks, just trace all of the vac lines and look for leaks... It's pretty straight forward, and there really aren't that many vac lines in our cars. You could also be leaking where the throttle body meets the intake manifold. Did you use a new gasket and make sure everything was tightened down?

As for the throttle cable, just look for any binding. With the intake off, look at the throttle plate and make sure it is making a relatively tight seal against the throttle body.

If everything appears to be mechanically in place, then I'd say it's your throttle position sensor (TPS).

 

[99EclipseRs99]

Thanks for the reply, I took the throttle body back off and inspected it to find nearly half of it was missing! Luckily i had some gasekt material laying around so I fabricated a new one and everything works perfectly. Thanks again for the help.
Ryan

 

[99EclipseRs99]

*Edit nearly half of the throttle body gasket was missing not the throttle body haha*