Bouncing Idle problem, unanswered at gay bmw-forum

[pogiboy9]

you replace your Air flow meter?, and it went away ?

[pogiboy9]

PS remember its only on Cold stair it bounces, after while it goes away.

[86325e]

And you checked for a leaky coldstart valve and tested your thermo time switch?

[pogiboy9]

thermo time switch? which is that

[86325e]

The thermo time switch tells the ECU when to turn off the cold start valve when the engine is cold. If its bad, it will cause the cold start valve to run an extended period of time, causing the idle to bounce and engine run rich. Its located on the thermostat housing next to one of the many sensors on already there. The FAQ I posted earlier lists how to test it and the other sensors.

[pogiboy9]

ARe you talking about the coolant temperature switch?.... the farthest one down of the 3 , nearest to the fuel injectors? i've tested the resistance if thats it

[86325e]

There is a coolant temperature sensor and a the thermo time switch (coolant temperature switch). They both have to be checked. Also a sensor screwed into that housing that is the water temperature sender for the meter on the dash.

Everyone has thrown a things on the table for you to check out and you haven't said if you checked those things out or not? You never said if you had checked to see if the cold start valve is leaking? If you are using brand new ICV and ICM or used, claiming to be working, ICV and ICM? If you checked all your vacuum lines (hard as rock, cracks, soft)? Bleed the coolant system? Did you read and actually go through that FAQ I posted, it steps you through and checks everything in the system that can cause this problem?

You mentioned you had the head resurfaced and port polished, who did that work?

[pogiboy9]

Would the fuel pump regular be compatible from the 325is ? to replace it