HELP! Can't figure out my high consistant idle.

j_ro0703 · 05-03-2008, 03:02 PM

Hey guys. im looking for some help. i"ve got a 2g gst and i cant figure out my high bidle problem. i've been doig alot of research and and pulling my hair out. ok the deal im having is when my car gets to normal operating temp i get a high idle. varies from 1400 to 2500ish. when i start it after it cools its fine but as soon as it warms my idle turns to crap. ive replaced the tps,iac,fiav,ect and most of the most of the vacs. im not sure if i should try to replace the egr or block it off. ive scanned the ecu and it throws a CEL saying its a system idle controll malfunction. And saying a code of P0505. the IAC. it also said that the egr system is ok. oh ive tried to adjust the BISS too. Ive cleaned the throttle body and the throttle cable is not in a bind. So i really dont know what else to do... im still a nOOb so any advise would greatly be appreciated. thanx

turbizzle · 05-03-2008, 03:07 PM

try adjust the idle adjustment screw on the top of the throttle body

j_ro0703 · 05-03-2008, 03:08 PM

i did but i want to find out why its doing that tho. i dont wanna CEL

RGdsmNewb · 05-03-2008, 03:09 PM

yeah i have the same problem, it's fine at first then starts revving high... i have no idea how to fix it

j_ro0703 · 05-03-2008, 03:13 PM

btw how do i det my pro pic to show.

Archametes · 05-03-2008, 03:44 PM

My car has the exact same problem, BUT no CEL... It came on once but after I erased it at never came on again. I still have the problem but no light is on. About the only thing i noticed and haven't done yet is the O-ring on the BISS screw. It looked a little worn but not too bad. I just haven't had the time to get a new one yet. If anyone has any answers to this or any other suggestions please let us all know.

Thanks, Mike

j_ro0703 · 05-03-2008, 04:56 PM

ok ive changed my egr valve. reset my ecu and no codes for my idle. also changed some vacuum lines. no i dont have any idle codes but, i have a code sayn that my TPS/ pedal position sensor A circuit malfunction. Code P0120. But no code in the book matches. ok i can see code for the tps but what about the pedal position? car idles better tho. if its not one thing its another. im getting really used to that happening

ekanddsm · 05-03-2008, 05:13 PM

How did you replace your fiav? I dont know how to do this?

j_ro0703 · 05-03-2008, 05:49 PM

my bad i got a lil side tracked. didnt mean to sat fiav. jus got alotta stuff on my mind. sry

appeartobelosin · 05-03-2008, 07:37 PM

Quote:

Originally Posted by turbizzle

try adjust the idle adjustment screw on the top of the throttle body

^^^^^^^^^^^^^^^^^
true true. or you could get a useful computer to tune your car and fix it electronically. dsmlink. your gonna need it anyways if you plan on upgrading anytime soon. dont waste your money on things like the apexi neo.....junk....i learned the hard way

j_ro0703 · 05-04-2008, 10:06 AM

ive heard about the dsmlink but im not ready to go that far yet. ok now its starting to get weird again. last night i went out driving and again it idles @2000k rpms. i unplug the IAC and no change no codes. i left this morning with it still unplugged. when it was cold it ran great then as soon as it got to operating temp it idles near 2k again. today im gonna swap throttle bodies with a buddy of mine a and see if theres a change. if that doesnt work could it be my pcm? im so confused at what to do at this point. i'll upate ya with the results.

talon187 · 05-04-2008, 10:24 AM

have you guys checked your isc units? thats what mine did when my isc went bad

wolfe06 · 05-04-2008, 04:47 PM

i had a problem similar to this, it was my throttle position sensor.

j_ro0703 · 05-05-2008, 07:14 PM

ok so today im swapped my tb with another one that already had a tps on it. i cleaned it really good. i put a new o-ring on the biss. i used the same iac that i had swapped before. i changed the lil tan plug that is on the fire wall directly behind the tb. im not sure ### its called. ok so now for the test drive.

its doing the same thing but now it feels like its running a little rough at low idle. still idles at norm when its cold but once again it idles high and now with a little surge. ### do i do now guys. im getting desperate. this thing is really beginning to stress me out. so any help or ideas would be a miracle for me.

ekanddsm · 05-05-2008, 07:31 PM

Block your fiav and try it again, The fiav raises your idle to 2000 rpms when cold to help warm up your engine.

Block it off, there is a tech article in here explaining how to do it, There are several different way to block the hole, but blocking it off will help this when warm.

You'll know when its blocked off perfect because you'll start the car and it will only be at idle, no higher.

Look it up, and try it. I did it on my car, it made me not look like an a-hole at the stop lights anymore.

talon187 · 05-05-2008, 07:33 PM

your isc is bad

j_ro0703 · 05-05-2008, 07:42 PM

i know its really embarrassing when you come to a light and see a hot a$$ chick next to you and ## car is idling @ 2000 rpms. i jus shut if off. ive got a 3 inch dp and a 3 inch greddy evo exhaust so you can definitely hear my car. but my one ? is ### are the chances of having to tb's that the fiav is messed up. idt my isc is bad. ive swapped it wit four of them this week wit no changes in my idle.

romeen · 05-05-2008, 07:57 PM

Try loosening the slack on your throttle cable. I had the same problem and this resolved it for me. Check out this post and notice what he says in the last part of first paragraph about how the heat affects the cable jacket in turn causing the cable itself to contract.

TPS reading at idle

Essential_DSM · 05-05-2008, 10:02 PM

And if it's nothing mentioned above. Check your ECU for any leaks. I Also had the same problem and found out that my capacitors from my ECU were leaking.

j_ro0703 · 05-06-2008, 07:23 PM

ekanddsm thanks for the advice. it did it today and messed with my biss and i think ive got it. but im thinkn its gonna a sum b####h to start when its cold. like in the early morn. ill update.

j_ro0703 · 05-06-2008, 07:24 PM

thanks everyone for the help. i really appreciate it!!!!!!

Enes_ · 05-06-2008, 08:28 PM

I have had the same problem with my gst and all i did was loosen the slack on my throttle cable..
IT seem to work for me

meliketoball · 05-06-2008, 09:26 PM

Replace the ISC and then if the problem is still there, try cleaning out your FIAV. It's underneath the TB. You'd need to take off the TB and unscrew the FIAV off the TB. It's not hard at all, try it. If that's not it, then check the TPS and maybe the throttle cable again.