So Many sensors, so little clarity...

[TigerTater]

Okay so recently my car has started to have problems starting after driving. Cold start is fine, starting after about 30-45 min is fine, starting after 4 hours is fine, its the time in between that when the car is still warm. I think the engine software thinks the car is cooler than it is, and its rich when starting, it takes several to 5 seconds to start. Once started everything runs fine, no issues. I have been searching and have narrowed it down to a few sensors.

The first is the Temperature sensor, coolant Part number 13621433077
http://www.realoem.com/bmw/showparts...15&hg=17&fg=30
Secondly is the Temperature sensor water/oil Part number 13621433076
http://www.realoem.com/bmw/showparts...=11&fg=15&hl=7
Lastly is the Temperature sensor air Part number 13621739510
http://www.realoem.com/bmw/showparts...=11&fg=40&hl=7

My problem is after doing some more searching it seems to me that after 2003 the Intake air temp sensor became integrated with the MAF sensor. So that part is now obsolete according to this thread: http://forum.e46fanatics.com/showthread.php?t=825755 Anyone have any ideas about which one contributes the most to the the hard start after car is warm? Thank Ya'll

[ZHPRegistry.net]

The part # ending in 77 is used for thermostat control. part # ending in 76 is used to determine fuel enrichment. Personally, from what you're describing I am not convinced that your problem is fuel enrichment. It actually sounds more like insufficient initial pressure. When you put the key in position 1 do you hear the fuel pump in the back work? Does it make a difference if you wait for the pump to stop and then fire up? How old are you spark plugs?

[TigerTater]

I always make it a point to turn key to pos 1 before starting, the fuel pump is working, its audibly loud after turning key to pos 1. The plugs are brand new replaced when I purchased the car no more than 10k miles on them. The start up is as I previously described regardless of key being turned to pos 1 to "prime" system. The cold start is fine and starting after several hours of being shut off is fine, its the intermediate time frame when its a hard multiple turnover seconds to start.

[Johnmadd]

I had similar issues in the e30 when I had a bad fuel injector.

[TigerTater]

I hear ya. Would it be throwing codes? Because I dont seem to have any check engine lights on or SES? Can a code be thrown and not show?