Hey guys, I finally decided to ask you guys for some help. It's been bugging me more and more. I don't drive my Evo that much but I guess I'll finally address my issue:

my fan randomly turns on and off it seems to suck power causing idling issues. Especially when I just turn on the car the fan will kick on a few seconds and off. Few seconds later again it will turn on then off. When I'm in the car and when the fan kicks on I can see my dash lights dim a bit and the engine will idle below 1k making it shudder. Has anyone else have had this problem before? I already got a new battery and sparkplugs. I did some research and someone had a similar issue but no one responded to it. The thread was dated 2009 so I thought I would just ask. Thanks!!

 

When did you do the last boost leak test?

 

Stock injectors or upgraded? I've seen injector latency issues cause this. When the fan kicks in the voltage drops for a split second and due to the latency value at 11 volts being wrong the idle dips for a bit due to a momentary lean condition.

It will also happen if your IAC is bad but you should notice other ill effects also.

 

Do you have the air on in the car when it does this?