Idle help
 

My S4 has a very high idle of 1000-1100 RPM. I did a check at the EZK connector between pins 2-5 and had .74nF. This is next to no resistance at all, but what should it be? Also between pins 3-5 (full throttle contact) i get the same result with no change depressing the accelerator to the floor.

So my question would be, is this a safe assumption to the problem?

Are you sure the Idle Stabilizer Valve isn't stuck?

I'm not sure of the pins and voltages, but sure if the throttle position switch isn't working it needs to be fixed, but I would not depend on that being the only problem or the root problem. Maybe its time to refresh the intake seals, hoses, etc.?

thanks Danglerb, my intake was recently off to remove my flappy and all vacuum hoses were repaired/replaced. Idle was like this before taking off the intake (thought it may be a vacuum leak). I have not checked the idle stabilizer valve, just thought it was odd i had the same values from the throttle position sensor in every position including WOT. Guess i need to spend a couple more hours trouble-shooting!

I don't know which model year S4 you have, so I looked at the wiring diagram for the 1990, which may not be the same. The throttle position switch has two switches that when closed are connected to ground.

Throttle position switch pin 1 goes to LH3 and EZK26
Throttle position switch pin 3 goes to LH2 and EZK5
Throttle position switch pin 2 goes to MP IX ground point.

Its an 89. I think the wiring diagram is different.

Does this help? I am sending you a PM.

This is what I show for the 89, not sure if I was reading the pin number wrong on the 90 diagram, my online image isn't that good of the WSM.

Throttle position switch pin 1 goes to LH3 and EZK26
Throttle position switch pin 3 goes to LH2 and EZK8
Throttle position switch pin 2 goes to MP IX ground point.