my new motor runs great, but when it's idling below 1000rpm the motor vibrates and so does the needle on the tach(autometer), it is really annoying! anyon ehave any sugestions

 

check your iacv shouldnt do that btu just check make sure its working properly what you cna do is just crank the idle adjustment screw out couple turns and raise it up a little for a stable rpm

 

thanks, I don't know that I want to just bandade the problem by raising the idle, I will if I can confirm that there is no problem. Anyone else having this problem? this is probably a really long shot but could the motor being built up (lower comp, heavier rods, etc.) have any thing to do w/it?

 

viren is right, IACV is the first place to look, i'd also check all the vaccum lines, and clean the throttle body...but seeing how you said it's a new motor, i would think the TB would be clean...check the vaccum lines.

 

is the IACV the one under the throttle body with the coolent lines going through it?
can I just clean it out or what?