Adjusting EACV Allen Screw?
 

Does anyone know what this adjustment is for. I cleaned my eacv yesterday and it make the idle much smoother. The only problem left is it has to get too hot before the idle drops all the way when warm. It will not drop at idle for about 10 minutes. The car gets warm enough but it won't drop till the fan comes on. I was wondering if this screw sets the temperature responce of the eacv and I could lower the temperature that the idle drops at by 10 degrees?

Hi,

Pulled this off another thread (mine). I too was working on this part and had a similar question about it:

Originally Posted by Darkelf View Post
There is a 4mm hex bolt on the side of the EACV and since is was worked on before, could opening that chamber have caused any problems? Should I check this?

TomO's Answer: The chamber should not have been opened for any reasons, but if someone did open it up and screw around it could've potentially ruined the IACV.

I looked at the schematic for the EACV in the Helms manual and I see where you would draw your conclusion/question.

I would say don't mess with it and take a look at your Thermostat. May be clogged and/or wrong temp for your particular car/situation.
Others areas I'd look at before digging in too deep into your EACV(expensive) would be chasing down vacuum leaks, make sure the EACV o-ring (looks like a figure-8) is actually doing its thing. Spray some WD-40 around it and check for changes.
Even look at things like the throttle cable. This one is sort of a long shot but it could be a smidge too tight. As this gets warm, it may settle, tho with thermal expansion I'd expect the opposite... whatever, easy check.
Clean your EGR valve. If it's clogged, could be affecting vacuum and thus the sensors that regulate everything on this car.
It sounds like a vacuum issue to me but I'm still learning so take it for what it's worth.

99% of cars don't drop the idle all the way till the engine's AT operating temperature. this is controlled by the ECU if there is one (not too many carbs here) and is NOT adjustable without going to an aftermarket ECU or bypassing the coolant temperature sensor, which will lead to greatly increased emssions and rough running till the engine really is warmed up.