Hi, I heard that Evos had idling problems sometimes anyway, but mine have just started. I have an evo III and i put in an HKS SLD (Speed Limit Defensor to disable the 180km/hr cutoff) and after I did that when i turn on my A/C it idles weird. Sometimes it idles high then goes down to about 8-900 rpm. When I have the eco setting on it idles really low, about 4-500 rpm and almost cuts off. Anyone else have this problem? I will be getting a new ECU sometime so that should fix the problem but until then i dunno what to do. I don't wanna adjust the idle up any more cuz i don't want it to idle high when i have the A/C off. Should I reset the ECU and drive with the A/C on so it takes that into account when setting again? Thanks

 

1st Gen Eclipses have that idle surge problem also. Some have hot surge (idle running too high or too low after the car is warmed up), cold surge (idle running too high or too low when the car is cold and just started), or both (Which i had). Usually people check the BISS, idle speed controller, and if all else fails change the throttle body with a used one (That one did it for me after i went thru a couple of those used TB's).

good luck... (or u can be like me and just live with it for a while )

 

yeah, i dunno. I don't really need the A/C too often right now, but with summer coming, it's gonna be really hot and i'm not sacrificing my comfort, lol. Thanks though. I'll probably reset the ECU and use the A/C when it gets hotter. Oh well, we'll see what happens, thanks though.

 

Very True... I haven't heard or seen that problem in the US Spec either... Just let the car heat up and it should be running fine then try turning on the A/C... I don't think it should Idle too high, if you still keep having the problem take it to dealer...

 

Yeah, i'm just gonna reset it and see what happens. I can't take it to the dealer. I'm in japan and it's a little different here. I bought it used from a japanese dealer and the warrenty is gone. But i don't need them anyway, there's auto shops everywhere if i really need it. thanks though

 

The ECU is smarter than most of us think. I learned this out a few summers ago.

When you turn the AC on while idling, the AC is supposed to pick up the idle so that the extra parasitic drag does not drop the RPMs too low to where the engine will stall.

But there is one catch to the idle pick up. The ECU will only raise the idle when the speed sensor sends a 0 MPH signal. You see, I was the type of guy who unplugged the speed sensor so that my mileage would not go up. But without it, the ECU did not know that I was at a red light, so the AC would kick on and the engine would stall because the idle was not raised. I plugged the speed sensor wire back in, and just like that my idling problems stopped.

If you are having trouble with the idle, it may be because you modified the speed sensor somehow. Try to trick the ECU that you are always going 0 MPH or km/hr.

Jeff

 

I am having the same kind of problems with my evo VIII and I have done o mods to it. Completly stock and when I have the air on at red lights it goes from 1000rpm to about 800rpm. Anyone have any ideas what this could be?

 

Im the kind of guy who swaps odometer with less milage .

 

My stalls out if the air is on and i come to a stop light any idea what that might be