Low Idle Problem

[CMF_Jon (2)]

Hey,
recently my k11 started playing funny buggers and has a low idle once warm - its around 400ish rpm when warm, even lower once I put the headlights on etc.
It started doing this the day I filled up at a servo I dont normally fill up at (filled with premium 98 as normal) and drove home to service it. Changed the plugs and gapped them as per manual. As soon as I started it up and let it get warm this is when the idle became low.
My k11 is also fitted with aircon and although the revs are low, it doesn't stall when you turn it on but revs drop considerably.
I've adjusted the idle speed back up to normal but revs still drop when aircon is on (it doesnt compensate and kick up the revs)
When I put my headlights on, the revs drop about 100rpm and they're dim when sitting idle. Once I'm driving theyre back up to normal brightness

Any ideas?
could it be an alternator thats just about cactus? - the voltage seems about right, just doesnt look like its up to putting out its full amount of current?

FYI, car has done almost 280,000 and looks to be original alternator

 

[CMF_asdame]

sounds like the Idle Control Valve is sticking. take it out to clean with carb/brake cleaner and free it up

 

[CMF_Greo]

Hosing out the control valve with cleaner helped with mine, when the idle was hunting.
Combined with the TB solder guide fixed my idle issues

 

[CMF_mycra]

when you clean the idle control valve be very care full not to damage or lose the o ring. the o ring is very very hard to find... but the problems ur having is exactly what happened to mine when i lost mine.

 

[CMF_Jon (2)]

asdame WROTE:

"sounds like the Idle Control Valve is sticking. take it out to clean with carb/brake cleaner and free it up

Cheers mate your a champ, did a bit of searching on the site and came across your post about this a while back.
Throttle body was re-soldered about 2 years ago, so knew it couldn't be that again.
Runs 100% better now, thanks guys