Idle Problem... not a chevy but need help
Thread Starter
Teching In
Joined: May 2007
Posts: 18
Likes: 0
Idle Problem... not a chevy but need help first off, i have a 1996 cobra with full exhaust and im having some idling problems......
so my car has been idling (1200rpms) weird since i got my tune, and I called my tuner (Nick @ Newtech Performance) to see if he adjusted the idle when he tuned my car. He said he wouldnt have touched the idle when he tuned it, but he told me to check the TPS and check/clean the IAC. I removed the IAC and cleaned it with Carb Cleaner and put it back on. I also cleaned the TB with Carb Cleaner too. when i fired up the car after cleaning, it started ilding between 1800-2000rpms and wouldnt go any lower. When i unplug the IAC harness, the Idle drops down to 800-900rpms (where it was before I got the tune). I got a new TPS because i wasnt getting any voltage readings, and it is still doing the same thing.
I tried to get some help on SVTPerformance, but i couldnt get too much helpful info. I had a friend refer me to you guys..
thanks in advance..
so my car has been idling (1200rpms) weird since i got my tune, and I called my tuner (Nick @ Newtech Performance) to see if he adjusted the idle when he tuned my car. He said he wouldnt have touched the idle when he tuned it, but he told me to check the TPS and check/clean the IAC. I removed the IAC and cleaned it with Carb Cleaner and put it back on. I also cleaned the TB with Carb Cleaner too. when i fired up the car after cleaning, it started ilding between 1800-2000rpms and wouldnt go any lower. When i unplug the IAC harness, the Idle drops down to 800-900rpms (where it was before I got the tune). I got a new TPS because i wasnt getting any voltage readings, and it is still doing the same thing.
I tried to get some help on SVTPerformance, but i couldnt get too much helpful info. I had a friend refer me to you guys..
thanks in advance..
TECH Apprentice
Joined: Jul 2006
Posts: 326
Likes: 7
From: Columbus,Ga
i would check the basics first, vacuum leaks. i like to spray carb cleaner around the intake, vacuum lines, etc... to pin point leaks. also fords are really bad about grounds i have seen them do all kids of crazy stuff do to ground problems.
When you unplug the iac, the car should die, if it does not then you have too much air coming into the system somewhere. This should be rectified, and is most likely the root cause of the issue.
If you have a scanner (ie, Xcal2/x3 device) datalog a value called "idle air intergrator" that will tell how much air adjustment the pcm is adjusting the base iac flow rate tables. Also datalogging desired idle rpm, could determine the cause of the idle speed increase.
If you decide that the Throttle body adjustment screw is messed up, do not just blindly adjust it, have your tuner command a 30% iac duty cycle in the tune, and adjust the screw so the idle air integrator is 0, this should be the last last last resort, after you have determined all of the other systems/hardware is correct.
Ryan
If you have a scanner (ie, Xcal2/x3 device) datalog a value called "idle air intergrator" that will tell how much air adjustment the pcm is adjusting the base iac flow rate tables. Also datalogging desired idle rpm, could determine the cause of the idle speed increase.
If you decide that the Throttle body adjustment screw is messed up, do not just blindly adjust it, have your tuner command a 30% iac duty cycle in the tune, and adjust the screw so the idle air integrator is 0, this should be the last last last resort, after you have determined all of the other systems/hardware is correct.
Ryan
Last edited by slow; Nov 21, 2008 at 08:36 AM.
Thread Starter
Teching In
Joined: May 2007
Posts: 18
Likes: 0
When you unplug the iac, the car should die, if it does not then you have too much air coming into the system somewhere. This should be rectified, and is most likely the root cause of the issue.
If you have a scanner (ie, Xcal2/x3 device) datalog a value called "idle air intergrator" that will tell how much air adjustment the pcm is adjusting the base iac flow rate tables. Also datalogging desired idle rpm, could determine the cause of the idle speed increase.
If you decide that the Throttle body adjustment screw is messed up, do not just blindly adjust it, have your tuner command a 30% iac duty cycle in the tune, and adjust the screw so the idle air integrator is 0, this should be the last last last resort, after you have determined all of the other systems/hardware is correct.
Ryan
If you have a scanner (ie, Xcal2/x3 device) datalog a value called "idle air intergrator" that will tell how much air adjustment the pcm is adjusting the base iac flow rate tables. Also datalogging desired idle rpm, could determine the cause of the idle speed increase.
If you decide that the Throttle body adjustment screw is messed up, do not just blindly adjust it, have your tuner command a 30% iac duty cycle in the tune, and adjust the screw so the idle air integrator is 0, this should be the last last last resort, after you have determined all of the other systems/hardware is correct.
Ryan
