car idles too high then too low?!?!?!

[skyvia686]

ok so ya ya ya you guys think its sirening up and down but its not. it will rev up to 2400 and stay there and im like wtf?!?! so i adjusted the throttle cables left them completely loose guess what 2400rpms again... thats when i was just puzzled. i found that a brake booster hose was cracked in half so i replaced that. nothing still. theres a hose that goes from the intake to the head with a big crack at the end by the head i replaced that knowing it wouldnt do anything. im out of ideas of if its a vaccuum leak or the iacv. if it is then how do i adjust it? and where would the possible vaccuum leak be? this is killing me.....

[skyvia686]

i wasnt too clear on the low part. ok so say if i was driving around town and i let off without downshifting to stop the car will either just die slowly or idle at 400 to 700 then die. this also happens when i first start her before i give her gas but she doesnt die. oiahsdoighoisag this is killing me!

[Forge_55b]

unplug the maf and see what happens, also the tps maybe. the low idle might be a leak somewhere but kind of hard to guess without being there to check things or experience it firsthand

[wings_s13]

what kinda engine? had this happen to my sr, the car would kick it into a high idle but after driving around it would die when u stopped. With my sr it was the timming, maf was loose and I have miss routed and cracked vac lines (thanks to the people who owned it before me..) so i would check that also a quick fix was to advance the ignition timming. check that hope this helps. good luck

[skyvia686]

i tried the ignition timing that didnt work accept i did crack a bolt of for the dizzy timing mount. just 1 out of the 2 (fml) i went front and back and nothing happened. sooooooo.... that cant be it. im guessing a vaccuum leak but why would it idle high then low? ive been hearing a bad ground too....

[skyvia686]

its a ka24de btw... its not that big of a deal but its just annoying and sucks up a lot of gas. and in a couple months ive gotta full rb20 swap for the s13. wiring harness already wired crossmember ecu trans driveshaft turbo manifold mounts all for 550 and its not stolen. so then again i can live with it it just gets annoying.

[dakota_lyons]

sounds too good to be true

[surreybc]

i doubt it is the iacv. check out your maf. wiggle the wires to see what happens. check your tps.

[skyvia686]

k thanks ill try. and to dakota its a former chicagoland drifters motor i saw it work perfectly when it was pulled and he upgraded to the rb26dett... and sold it to one of my friends for cheap so hes sellin it to me for even cheaper. the motor is in my garage now picked it up today :D

[hOngsterr]

try looking at the PVC pipes
and it might be the break booster itself,

[xX5Tb0nE7Xx]

Sorta the same thing was happening to me on my sr. I found the throttle body wasnt closing all the way, so when i pushed on it by hand it would idle right where its supposed to be at. I think it got bent during shipping or something you could check that maybe.

[skyvia686]

i really didnt take a look at it but ill try. thanks. and if its the brake booster itself ill kill someone because my brakes are really stiff but doesnt stop easily. i think i just might need some new brakes though...

[I LUV MY S13]

idle air control valve..guarantee its ur issue

[skyvia686]

how do i adjust it because its def not busted its not bouncing like a bitch......

[surreybc]

how do i adjust it because its def not busted its not bouncing like a bitch......

the iacv cant supply enough air to get to 2400 rpm. force your throttle plate shut at idle and see what happens.

[skyvia686]

already have. nothing at all just a high idle... wtf man im so puzzled right now. and its not overheating so theres no air bubbles for the coolant. wft!!!!!! :-/

[surreybc]

already have. nothing at all just a high idle... wtf man im so puzzled right now. and its not overheating so theres no air bubbles for the coolant. wft!!!!!! :-/

close the hose that goes to iacv and air regulator. if that does nothing , you have a vacuum leak. spray some carb cleaner to see where your leak is.

[skyvia686]

k ill do that later thanks.