cold rain, idle suddenly rise +200

[tino]

I don't know what happend with my iacv/ecu. idle perfect , but when rain comes at the middle of my drive, my cars rpm rise from 750 to 950-1100.
whats wrong ?
seems the cooler of my engine result the higher rpm. I notice when heat indicator at dash only 1/4 then idles more up, when 1/2 (normal temperatur) then idles good.
At cold start ? i should wait about 5-10 min before rpm sattle at 750.
resetting ecu couple times, not work.

pls hlp what should i do ? re-map ecu ?

[xfactortype1]

check fast idle valve

check fast idle valve. make sure the the spring is seated tight..use screwdriver to tighten down. most likely cause

[tino]

I tought it was my fitv, replace with brand new, still the same thing.

[xfactortype1]

if it only happes in rain..then moisture is getting into something thats making your idle raise. hmm check connections plug and vaccum tubing for cracks. moisture could be in dizzy or spark plug wires not seated tight

oh and i cont understand " when rain comes at the middle of my drive"..when your driving the car..a high idle on warm-up is ok it reaches operating temperature..then should slowly drop to..750. if it fluctautes then not good.

[tino]

not only in rain, but whenever engine slightly cooler ..like cold raining, driving down from the hill. just when heat indicator at dash bellow 1/4 then it goes.

How can i kept idle stable at 750 whatever engine temp., because i use auto tranny, & it is not nice to shift the tranny-lever (car jump like it will damage my motor mount), or hold brake pedal at traffic at near 1000 rpm.