M52B28 swapped - engine cut off when cold start

[ecsk]

This happened recently to my E30 with M52B28 swap. Start the car in morning, idle drop immediately and die. I need to hold the throttle to maintain the idle for about 30 to 60 seconds, then it'll idle ok.

Where should I start to troubleshooting ? I suspect it could be coolant temperature sensor.

[Dgerry]

Check for vacuum leaks, closely check the hose that runs to the ICV. The intake boots can crack on these as well if you are using a stock style (non silicone). That is where I would start.

[MrBurgundy]

Yeah, check the temp sensor

[haaken675]

I had something very similar happen to my e39 when I first got it. Previous owner thought it was vanos seals, which I replaced. Still had some cold start issues and I replaced the MAF and it mostly went away. I still had a hard time starting on cooler mornings, and I eventually arrowed it down to likely being a dirty ICV. I would try the ICV first and keep checking from there.