you know the usual warm up procedure when your fc is warming up?
how it jumps revs to 3k and slowly idles down as it warms up?
these days my car seems to be forgetting the warming up part.
it just revs up to 2k ish and idles from there till warm up.

recently been acting like this and was wondering if something is up.
thanks

 

mine never goes to 3k either. i get up to 2-2.5k and then it drops down to 1. after around 10 seconds it jumps up to 1.5k and idles and then takes 5 minutes or so to drop down to my 800rpm idle.

it makes sense that it takes 5 minutes to drop down to a normal idle since its under 30*F here. But I dont understand why the idle drops and then raises back up. the other oddity is it ONLY happens first thing in the morning. never at lunch time or at night...

 

All of my electronics and engine are in good working order and mine does the same. I think it is normal.

 

Believing your car to be an S4, you have two items which creates the high idle upon start up that progressively drops to normal idle. The"Air Bypass solenoid" should cause the rpm to rev to 3k or so for 17 seconds before dropping to around 1.5k where the Fast idle/Thermowax unit then slowly drops the rpm to 800 rpm or so.

The Air Bypass engages only when the coolant is above a certain threshold and any coolant temperature below the threshold upon start up will prevent the solenoid from enabling the 3000 rpm rev. The cooler/colder weather might explain why it is not engaging. If you jumpered the two wires to the coolant sensor it would force the high idle rev to engage upon start up if you wanted to check the operability of the unit.

 

okay, so it seems like my fc isnt sick yet.
thanks guys.

 

It doesn't need to rev up to 3k RPM anyway. A lot of people want to get rid of it actually.

 

I'd like to get rid of mine. I'm Rtek'd and it still does it..??

 

Startup below ~5*C and it doesn't do the 3k AWS (Accelerated Warmup System, or aka Accelerated Wear System, designed to warmup the cat quickly for emissions, at the expense of extra wear); on an S5 at least, if you start the car with it in gear (ie., clutch in, stick in any gear position), it will skip the 3k startup also. The 3K idle can be disabled on S4's (search should find it, you unplug one of the relays on the solenoid rack, iirc); on S5's I'm unaware of any method that works with the stock ECU - I looked into it years ago, one that I found said it worked on S5 in fact just left the car so it wouldn't start.

In any case, no AWS is a good thing as long as the car runs/idles normally otherwise.

 

To disable the S4 version it requires disconnecting the two wires connected to the temp sensor that is part of the system.

 

yeah mine has just started doing it as well. As long as it warms up fine it should be ok