S5 TII with all emissions removed/blocked off. basically stock besides removed things.

(also, this is a JDM motor with JDM engine harness, front body harness, i did a RHD swap on)



what i did/checked:



tried a different boost pressure sensor

tried a different MAF sensor

tried a different ECU

sanded down all grounds and ground prongs for clean connection

adjusted the TPS every possible way

cleaned TB, UIM thouroughly

replaced all vacuum hoses and siliconed metal to metal areas (the correct way) everywhere

checked for vacuum leaks every imaginable way

*even ran a water hose over everywhere air could escape to make it bog and change idle





ok, so if its not any of this, what would make my idle bounce from 1000 to 1500!?!?!?



side note, if i raise the idle to about 2000+ it dosnt bounce. dont know if that means everything...





any idea would be helpful. im out of ideas and im about to do something i havnt done in a VERY long time. pay someone to fix it!!!! NOOOOOOOO!!!

Put that Power FC that your selling on there and call it a day.

timming off by chance. and wasnt there something about the jdm computers with us fuel that would make the motors do strange things . cant remember what it was but i thought there was something about that.

lol...your not the first person to tell me to do that.

timing wouldnt make it bounce. or atleast, i never seen it do that. and i tryed a US NA ECU and made no changes to it...

i have seen idle bounce on motor with the timming off. most of them where na carby cars but i have seen a few of ower race motors do that too that are injected

Cleaner simpler.

maybe... but the motor hasnt been rebuilt and i have never removed the CAS, so i dont know how the timing would be off.







i might just throw the A-pexi on there. i'll give it one more week. the problem is no one around heres tune A-pexi. thats why i was selling that one and swapping it for a Microtech i have.

one more thing. my car did a goofy idle bounce when the secondary throttle plates where missadjusted. i did a cosmo re throttle body mod with fd plates( board out the re tb to the rew size) when i put it back together the secondary plates where cracked open just enuff that the idle acted weired. what type of intake do you have on it, stock air box or something else....... dont hate on me for askin stupid questions just i have seen alot of oddities over the years and an open mind may trip a result in a repair.

the intake and manifolds are basically stock. stock TII manifolds and throttle body. but the throttle body i ported myself and removed the secondarys in it.and the intake i kinda just made.



heres a pic so you can see my intake. i got the filter with the front clip. and uses a piece of tubing i had laying around.



(i changed from the charge pipe and BOV back to stock, hit the hood)



Attachment 17514



Attachment 17515





and heres the TB ported...



Attachment 17516