Idles too low (accelerates with hesitation) after cold start

[CalmGuy]

Hi guys. I own the european 1993 318is with M42B18 and manual transmission.

Few weeks ago I have noticed that something is wrong with the car. There are two sympthoms and they both appeared in about the same time. So I don't really know it is the one fault or more of them.
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To begin with, the car doesn't run properly after the cold start (when the engine is cold). As you can see in the video, it cranks a bit too long and after it the engine runs poor, idle is too low and a bit rough. During this time I can rev the engine only if I push the pedal slowly, because if I push it quickly, the engine tends to die, struggles to work. As I said you can see and hear it in the video. This happens for a minute or less and later there are no problems with starting (however once this happend with warm engine).

http://www.youtube.com/watch?v=wy13Sy9l_qM

In addition to this, sometimes while driving the car (doesn't matter cold or hot) I can feel that it starts to accelerate itself. Idle is too high - ~1500rpm. This happens for a short period of time. After few minutes or less the idle drops.
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Dear people, could you share your ideas what is possibly wrong with my BMW?
I had the car scanned for a fault codes - it showed the temperature sensor. The sensor's plug is OK, it gets right voltage and so on. Also I've changed two of them - no difference. Moreover, I have cleaned the idle control valve, changed it with another - also no difference.
I don't really know what else could be wrong. Please give some help. :rolleyes:

[JH ///M]

My e36 318is (m42b18) has a similar problem

When i cold start it it idles rough  800 rpm down too 400 and then 800 rpm again.

the idle drops a few times and then it gets better,

i think its old hardened or cracked vacuumhoses.

[romkasponka]

Totally agree with words above. Check all air hoses. Prolonged cold start could be also because of fuel mixture is too lean and the reasons could be various: temp sensor, lambda sensor and so on. Go and do diagnostic somewhere diagnostic and/or by USB diagnostic cable on eBay and with some experience you will be able to trace where is the problem.