1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

1G High RPM with after market throttle body

Posted by Austn17, Apr 8, 2020

Please Support STM Tuned
Please Support Feal Suspension
  1. Austn17

    Austn17 Probationary Member

    3
    2
    Joined Apr 8, 2020
    Tooele, Utah
    91 GST. i had bought a after market throttle body. no place for the idle stop switch. after install. cold start idles fine. idle is fine as long as i dont touch the throttle. once i start driving it it'll stay about 4k rpm on stops and shift through gears. do i need to some way mount the idle stop switch, stand alone ecu?
     

    Attached Files:

    216  1

    1991 Mitsubishi Eclipse GST
    14.00 @ 85.00 · 1G DSM
    Loading...
  2. DSMPT

    DSMPT Proven Member

    755
    377
    Joined Jun 12, 2014
    Japan / Mexico, Arizona
    First, you should check the throttle cable moves smoothly and the throttle plate open/close smoothly. Sounds like the throttle plate is not fully returning once you open the throttle.
     

    Drag Race Build 2K  3

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    Street Build 2K  4

    1998 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
    Loading...
    Austn17 and ThunderChild like this.
  3. jed344

    jed344 Supporting VIP

    666
    70
    Joined Jan 10, 2008
    Waterville, Iowa
    I agree, maybe your cable is to tight? set tension with the motor warm. Not uncommon for it to idle high if set when cold.
     

    1K  26

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
    Austn17 likes this.
  4. Twinturbo120

    Twinturbo120 Supporting VIP

    377
    17
    Joined Aug 14, 2010
    Miami, Florida
  5. Vegas smith

    Vegas smith Proven Member

    3,059
    1,605
    Joined Dec 2, 2002
    Houston, Texas
    There's a lot that could be wrong here. No stop switch is a bad thing and needs to be replaced unless that aftermarket tb is magically adjusted to the correct location. It's also bad because the ecu will not know when he car is at idle or when throttle is pressed down and will cause fueling issue. If you have ecmlink you can get around this lack of stop switch. Throttle cable is probably messed-up/incorrectly adjusted if you're' saying it's idling at 4k. We haven't even gotten to fiav and isc issues.
     

    Street Build 4K  10

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
    Austn17 likes this.
  6. ATF 2GTalon

    ATF 2GTalon Proven Member

    78
    14
    Joined Oct 28, 2002
    NYC, New York
    Also good to check if your FIAV gasket is not leaking. You're getting too much air in from somwwhere.
     

    Street Build 687  1

    1995 Eagle Talon TSi
    13.7 @ 105 · 2G DSM
    Loading...
    Austn17 likes this.
  7. jed344

    jed344 Supporting VIP

    666
    70
    Joined Jan 10, 2008
    Waterville, Iowa
    Think of it this way, if your cable is NOT to tight. Then air is leaking somewhere from TB or intake manifold. I actually had a high idle today around 1,500 rpm. After playing with idle tuning I had to reset biss adjust to get ISC to around 30 at idle. There is a lot that can cause it. Start with the easy stuff.
     

    1K  26

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...

Share This Page

Support Vendors who Support the DSM Community
ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications OHM Racing RixRacing RockAuto SouthBay Fuel Injectors STM Tuned Track Decals Track Sculptures VR Speed Factory