So I took the HKS ground kit of my WRX I am selling to put on my evo. Hooked it up to the ground points near the battery, near the passenger headlights, on the in take manifold, and on the valve cover. Started the car and it was idleing above 1000 rpm and that is after driving it for a while. So I reset the computer and took the kit off. Still idleing too high. I'm lost, what the heck happened? Anyone know?

 

first of all y do you put a wrx kit on the evo

 

Your Evo is angry at you for polluting its engine bay with a SUBARU kit...

 

Check to see if you're at normal operating temperature yet If so adjust the screw on the throttle body or look for any unconnected plug (mas, etc).

 

this is your idle stepper motor.

this is a stepped motor that is checked and reset after each service to a point value of step 9(start). this motor advances and retards depending on cold start etc etc. after a while the value it starts at will creep up and it will run out of room for it to operate over its full range. I think it goes in a range from 0 to 120 and needs 40 odd steps to work. i.e if the starting point gets above 80 then it wont be able to cover its full range of 40 steps. (figures are what i roughly remember and may be wrong)

This is a common occurance once the battery has been disconnected. sometimes it will sort itself after a couple of hundred K's. otherwise dive up to your local dealer who will reset the stepper motor with their MUT equipment. (5 mins tops)

hope this helps

EDITED TO SAY DONT **** WITH THE SCREW ON THE THROTTLE BODY..THIS ONLY CONTROLS THE AMOUNT OF AIR BYPASSING THE IDLE SPEED CONTROLLER AND WILL **** UP YOUR MIXTURE ETC.ETC

 

I've mess around with this screw and no problems yet. Knock on wood It should only effect idle but don't quote me on this.

 

this idle problem is a very common issue on ALL to date evo's . the stepper motor is prone to failure and going out of adjustment. if you adjust the amount of air bypassing the motor you will be fooling the engine. if once the stepper is reset at service you will then have a problem manifest itself.

it aint worth playing unless you got the mut. you will be playing with fire.

the idle screws dont move by themselves. so it makes sense not to play at hiding problems. by disconnecting the battery the ecu has effectively been reset and will have to re-learn certain perameters.if the stepper motor is advanced at this point when the battery is re connected it will see this point as zero...hence your problem.

 

I'm in agreement with you but I think the screw was there to allow for adjustment or else they would have block it like most new cars. I don't know if his car is stock or not but if it was my car and the rev was at 1300 rpm under normal operating temperature I would play with the screw.

 

there is normally a rubber grommit/plug in there to stop idle thumbs.


If it were my $30000 car and it developed an idle problem. i would get my fat **** down the dealer and get em to sort it. sharpish.

 

good time to run a standalone and anti-lag! LOL. more air getting thought the engine means a bigger bang in the exhaust manifold! soory i will stop putting up useless posts about anti-lag!

check all the conections. reset the ECU, have a mechanic run his eyes over it...... apart from that im at a loss!

CHris

 

Thanks for the info on the BISS.

 

Wow, this thread was like a year old. If you are wondering what the problem was. The ECU needed to reset its self. It just took 2 weeks to reset and the idle aventually went down. I made my own ground kits I have 2 sitting here, they are the same as the Hyper Ground kit more or less. $20 each. PM if you want