the newfound problem... a hanging idle

[droptopford 5 0]

over a period of a couple months now, everytime i start my car it seems to get worse, but it turns over a couple more times than it even used to, and the idle surges to about 15-1600 roms and hangs there for about 5 seconds then falls to about 1000, im only questioning what goes on because my car only used to jump to about 1300 rpms for less than a second, fall to about 1050 roms, then in a matter of a few seconds, it would fall right back down to a normal cold idle for me(about 800ish roms) the normal hot idle would be around 650 rpms, and now it only idles at about 800 rpms. could a dirty maf be the cause? and could my maf even be dirty ADAIN??!! its only bee a few months since i last cleaned it) im not seriously worried, it is just getting to be a higher and higher rpm as time goes by, so im just trying to get some ideas

 

[BlownFiveLiter]

You could try pulling codes, but you may not come up with anything. Try cleaning your IAC, and resetting your idle, too. I think it's in the sticky at the top, otherwise, a quick search will find info on doing it, since it comes up every couple weeks or so.

 

[mo_dingo]

do a search on adjusting your idle. Millions of threads on this issue.

 

[91LX_5L]

do a search on hanging idle there are many threads filled with usefull goodies.

 

[BlackVert]

sounds like an air leak to me. probably a hose came off somewhere or broke for some reason. i have one right now i'm looking for (as time permits). mine is somewhere under the upper intake.

while the car is idling, take a can of carb cleaner and spray it at different places along the intake track and also on the driver's side around the lower intake. when the idle changes, there is your leak.

if there is no leak, then it is most likely a bad (sticking) idle air control (IAC), also known as the idle air bypass valve (IAB). cleaning them doesn't really work, so you should just get a new one if it gets that far. they are like $40-$60.