I searched but found nothing relevant or helpful to my problem, so yeah.

It's in the low 40's now in the mornings (I use my 7 to drive to class), and will only get colder! I go out to start it, it revs to 2k in neutral (usually to 3k when it's warm outside), then the idle jumps around 600-900 for a while, then it hovers around <500, then it stalls. I start it back up and the revs don't jump unless I give it throttle.

It ends up repeating the process until the engine is warmed up and I drive off. Everything is fine after that

 

Check your water thermo valve and fast idle cam, it should be raising and maintaining your idle at 1500 for a while at that temp. The cam can sometimes get stuck, the throttle plates can sometimes get stuck, and the water thermo valve can sometimes get clogged. With that low a temp, as you suggested, the 3k startup shouldn't kick in. If the idle is jumping, I might recalibrate the TPS, and possibly idle speed and idle mixture as well.

Check this idle chart:
http://howto.globalvicinity.com/gv_w...i=60&co=1&vi=1

and here's TPS adjustment:
http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1

...and finally idle speed and AFR
http://howto.globalvicinity.com/gv_w...i=61&co=1&vi=1

 

I should probably add that I have an S5, so I guess that last link should be different?

 

Tps

 

I believe all an S5 can do is adjust the idle speed with the air adjust screw, and not the idle AFR. To adjust the idle, warm up the car, ground your test connector, and then turn the air adjust screw till your idle is 750.

edit: then unground the test connector when you're done!

 

I updated the last link to show how to set the idle speed in an S5 too.

 

Intake vacuum leak.


-Ted

 

im having that prob myself starts, go's to 2k then comes down and dies once its qtr way warm though it will hold idle then once fully warmed idle's normally at about 750 as i have'nt been using my fc as a daily i've not bothered with it, but im going to start using my car daily now so would like to know what outcome u had was it simply a case of adjusting the idle with the test connector ground or was it a intake leak any feed back would be most helpful

 

So this system should only cause the idle to go to 3000rpm when the temps are around 60 or warmer if i understand this correctly. I had noticed that on my 86 when i start it in colder temps(50 or lower) that the idle was only going to about 1500-1800. I thought i had a problem until finding this info. Do i understand correctly that my is pretty much acting as it should?

Thanks
Kerry

 

Sounds correct to me!