Here is what I got, 2.4 block, HKS 272's and EMS

Ok so im going to try to explain this the best I can. I start the car, it idles at 1400 and once warmed up idle falls to 1100 and it idles SOLID. I drove the car around for 20 minutes some on side street some on the highway, no problems. When I let off the gas the idle falls to about 1400, idle surges for about 2 seconds, then smooths out at 1100 again, this is normal for me, no problems.

Now I turn the car off for 15 mins, start it back up, idles great, take it out for a drive, im on the highway in 5th gear at about 2800 RPMs, I press the clutch and the RPMS shoot to 3200 and stay there, I give it a little gas, the throttle isnt stuck. I give it a quick burst rev to 7000 and then the idle falls back to 1400, surges then back to 1100 like normal. I put the car back into gear, get it up to 3000RPMs, press the clutch again, same thing, but now the idle jumps to 3500 and im not touching the gas at all. I finally get it home, I was downshifting and using the brake to get the RPMs down while driving, I get into the driveway, come to a stop, pop the hood, its still idling at 3500 mind you, I physically check the throttle and its closed. This has been happening for a few days, I replaced the idle speed motor, it worked fine on short drives right after warmup, but its happening again.

Anyone have any ideas? I am open to any suggestions at this point? If you post your email I can send my cal file.

 

Sounds like your Idle% vs Target table needs some work. It will definitely make the idle surge and get stuck if it is not close.

Watch the "Idle Learned Valve" is it pegged at a negative percentage? You want to get it close to 0%. I usually keep it about -2% to -4%. Make sure you tune with the lights and stuff on so when you do use them it doesn't get all out of wack.

I usually get a car to idle very good at 900 rpms then increase it to 1000, 1100, 1200, 1300, 1400, and finally 1500. After 1500 rpms I then level it completely out flat to 3000 rpms. On 03's Evos the IAC could not control anything above 1525 rpms it would surge like crazy after revving the car. 04+ the IAC motor is different and has a higher range of control but who needs a street car to really idle above 1500rpms?

Also test with A/C on and off as well. You may need to increase the "Idle A/C Load Comp" between 9 to a little over 10 is what gets it close.

Here is a screen shot of my old cal for my AMS 2.3L and AMS race head with JUN 272 cams. Car idled perfect (for a huge cam) from no joke 800rpms and up. You have smaller cams but this is to give you an idea.

 

Just also make sure you pay attention to the max idle feedback rpm and make sure it isn't set too high. Not above 2000rpm for sure but each tune is different. You can also take a look at the RPM Offset vs TPS table, zero it out to see if it will stop this behavior as well.

 

thanks for the input guys. I just sent my cal file to itzwolf for review

 

I would encourage you to work on this as well. It can also cause your RPMs to "hang" if you will after throttle lift on decel. I pretty much calibrate the car to idle at every RPM between 800 and 2000 then tell it where I really want it to be.

 

it sounds to me like someone reset the ecu as in pulled the fuse out in engine bay. i know i did this by accident and couldnt figure out why it was doing the exact same thing as your car does. im still stock 2.0 but if you reset ems it will idle high until it teaches its self back to its original map