Cold Start Problems.

[85_318i]

Hello all,
So I have been fighting this darn cold start problem since I got this car, when I go to start the car for the first time that day, so when it is cold, It will fire right up and the r's will go up to about 1000 and stay steady for 3secs and then the idle is erratic till the car warms up and then it runs like a top.
Since I have had the car I have replaced the starter, thermo time switch, water coolant sensor, all new gaskets from the bottom up, new fuel pre-pump, new ICV. I have put a lot of time into this car. I did not pay for the car so the money I have put into it i dont mind, I just want this damn car to cold start. I have also checked the cold start valve per Bentley and everything there seems to be fine.
Please help my brain totally hurts
JD

[Will_318i]

mine does the same thing with the rpm's going to or above 1k and then it will drop down after... 5-10 seconds? But my idle isn't erratic... Hopefully you can find your answer. GL!

[85_318i]

So possible fix!! Thanks Bentleys

So I was bored today and racking my brain somemore and I was reading about my coolant temp switch, and apparently that controls the idle by telling the l-jet how much gas to give the motor, I am dont messing around and will get the part tomorrow. If you go to realoem.com and under engine and sub category engine cooling it will show you the schematic and part number. Check this part if you are having an erratic or jumpy idle, along with the basic stuff. Check for continuity, per bentleys, pull white wire and check if there is, the temp is hot if there is not then the engine is cold, any problems with that test replace. It is a 60 dollar part.
Gonna try in the morning will let everyone know how it goes.
Thanks

[Cyrix2k]

So I was bored today and racking my brain somemore and I was reading about my coolant temp switch, and apparently that controls the idle by telling the l-jet how much gas to give the motor, I am dont messing around and will get the part tomorrow. If you go to realoem.com and under engine and sub category engine cooling it will show you the schematic and part number. Check this part if you are having an erratic or jumpy idle, along with the basic stuff. Check for continuity, per bentleys, pull white wire and check if there is, the temp is hot if there is not then the engine is cold, any problems with that test replace. It is a 60 dollar part.
Gonna try in the morning will let everyone know how it goes.
Thanks

:crazy: Which sensor is this exactly? I think the wires that run to it might be deaded on my car. Just more stuff to fix I guess.

:edit: I just realized this for an M10 so your sensor would be in a different location I guess.

[85_318i]

:crazy: Which sensor is this exactly? I think the wires that run to it might be deaded on my car. Just more stuff to fix I guess.

:edit: I just realized this for an M10 so your sensor would be in a different location I guess.

Yeah, i am sure its mostly in the same place. On the M10 it is on the water inlet housing, it is next the thermo time switch and coolent temp sensor.

[Chabs]

I have cold start problems as well. I need to turn the key several times before it actually starts and then let it idle before I drive it. I really would like to know how to fix this..

[Cyrix2k]

Yeah, i am sure its mostly in the same place. On the M10 it is on the water inlet housing, it is next the thermo time switch and coolent temp sensor.

cool, thanks. I need to fix that.

I have cold start problems as well. I need to turn the key several times before it actually starts and then let it idle before I drive it. I really would like to know how to fix this..

Does the M10 have a cold start injector on the intake like the 325e? You might want to check that.

[85_318i]

cool, thanks. I need to fix that.

Does the M10 have a cold start injector on the intake like the 325e? You might want to check that.

Yes, yes it does. I know that for certian. Well the update is that I have not fixed the problem yet. I have replace thermo time switch, which is just for cold starting, replaced both coolant sensors per bentleys, and switched out cold start valves.
I am starting to think that my in line fuel pump is the culprit, but I thought that about the sensors too. So I need some help. One of the fixes per bentlys is fuel pressure, I started my car and listened to the in line and as the idle jumps the pump jumps too. So in theory, the cars idle is jumping because the pump is? But why does it stop completely when the car is warm?
This is what I cant figure out. If it was a vacuum leak it should do it when its warm too right? IDK!!!!
Please help guys!!! I am outta ideas.

[Cyrix2k]

Sometimes vacuum leaks seal themselves up as the engine bay gets warm. BTW, I just replaced the throttle body boot & ICV tube and the car went from barely starting and idling horribly to being perfectly smooth! HUGE difference.

[sixty6falcon]

Not sure if you ever resolved this issue or not, but I thought I'd chime in. I had this same problem when I bought my car. I would crank on the car for 45-60 seconds on the first starup of the day in 30 degree weather. I figured out that the previous owner had done some work and mixed up the connectors on the temperature time switch and the temperature sender. I swapped them around and she started right up.