I have a 1993 240. If the air temp is under 80F, cold starts are immediate and problem free. When outside air temps are HOT, like we've had the past few days of 90+, cold starts are problematic. The engine has to crank for at least 5 seconds, and when it starts, it is partially flooded, gives a puff of blue smoke, and takes a few seconds to level out. Why is this happening? Is the fuel mixture always a bit rich, but only noticeable and problematic on really hot days when trying to cold start? If the mixture is always a bit rich, maybe that explains why the car starts to immediate when the weather is cooler. Would anyone here have a good explanation for this? BTW, I did replace the temperature sensor and it made no difference. Also replaced the fuel line "check valve" (can't remember what it's called) on top of engine. No differences noted with this change either. Or is this a problem all 240s have? Thank you for your feedback. Hugo