hi , i have a 89 gtst skyline that has a strange idle problem like hunting but harsher revs rise to about 1400rpm then drop suddenly to 900rpm, but whats weird is that if i put the fan on full and turn the lights on it calms down and idles smooth at 1000rpm..and also once i turn the key off and turbo timer takes over it idles smooth aswell, i have unplugged the turbo timer and problem is still there i have followed wires back to ecu and found a white with red spots wire looks cut but mayb its been like that the whole time (any 1 know what its for), please help i think it might possibly be a earth issue somewhere, i am a truck mechanic so this is a bit fiddly for cant fix it with a hammer lol