OK before you say search I did....My idle is bouncing from about 800-3000 rpms back and forth. Also while driving it feels like the car is giving itself gas up to about 2400 rpms and then just bogs......Recently replaced the IACV so that is ruled out. Any suggestions or ideas would be great.

 

well happened to me before found out i had wrong intake manifold gasket. or cud be ur intake manifold gasket is leaking or broken. if the idle flucuates like that cud also mean a vacum leak check all ur hose lol

 

Same thing happens with my 95 ls except mine only goes from about 1000-2200

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93JDMB18C &raquo;</TD></TR><TR><TD CLASS="quote">OK before you say search I did....My idle is bouncing from about 800-3000 rpms back and forth. Also while driving it feels like the car is giving itself gas up to about 2400 rpms and then just bogs......Recently replaced the IACV so that is ruled out. Any suggestions or ideas would be great.</TD></TR></TABLE>

need info: car, model, engine mods, mileage, etc.... blah blah blah

 

sounds like a vacuum leak.

did you recently replace your intake manifold?
your intake manifold gasket could have gone bad or there might somehow be a hole on your intake manifold....

basically air is getting into your engine and not being stopped by the throttle body...
when enough air gets into the opening it closes itself for a moment causing your rpms to drop again to idle then it opens up again and your rpms go back up till it closes up again.

 

agreed with everyone. once i replaced my intake manifold, my throttle body gasket was leaking and that causes that "jumpy idle" you're describing.

sounds kinda silly but if you're a smoker or have a smoker friend, blow smoke around that area and see if it gets sucked in anywhere it shouldn't. that's how i found my leak.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lude27 &raquo;</TD></TR><TR><TD CLASS="quote">agreed with everyone. once i replaced my intake manifold, my throttle body gasket was leaking and that causes that "jumpy idle" you're describing.

sounds kinda silly but if you're a smoker or have a smoker friend, blow smoke around that area and see if it gets sucked in anywhere it shouldn't. that's how i found my leak.</TD></TR></TABLE>

wow ive always used liquids but usually if im working alone im smokin... im defitnatly gona try this.

 

 

it is your idel air controle valve. It is on the back of the plenom right past the throttle body. take it off and there will the a valve that screws itself out and just screw it back in and clean it with some carb cleaner.

 

I stated above that is it not the IACV i just replaced that so I am quite sure that is the not the problem.

BTW it is a 94 B18C with about 60k on it

Also I have no touched the Intake manifold recently minus replacing the IACV but I didnt remove the Manifold