slamdunkcivic

The idle in my B16 is fine 99% of the time, I have noticed that if I get stuck in traffic or a drive thru etc and the motor gets a bit warm, not even enough for the fan to cut in but warmer than normal driving, the idle starts to go up to just over 1K and back again in a rythum, as it gets hotter (longer in traffic) it gets worse and has gone up to 2.2K and down again before, still to a beat.
Soon as I start driving and it cools to normal running temp its fine.

The coolent is bled and full and has been untouched for about a year and this has only just started.

I searched but nothing seemed like my problem, all the results seemed to be at cold or all the time. So sorry in advance.

CardDealer

Check your vacuum lines for any loose connections....

b18cKoupe

check if the fan is coming on if not it could be your fan swith on the thermostat housing

slamdunkcivic

fans coming on and all vacuum seem fine.
If it was vacuum wouldn't it do it all the time and not just when hot?

junkyardd16z6

Check your Fast Idle Thermo Valve make sure the white plastic screw inside is fully seated...

slamdunkcivic

Thanks, where about is that located on the motor?

dantastic

under the throttle body if you have an obd1 throttle body. how's your cooling system doing? any CEL's? i had a similar problem when my coolant temp sensor wiring was bad.