Hard start on '95 525i
I've been working on a 1995 525i that consistently starts hard when it is cold. Once it's been started, you can shut it off, and it will start right back up. After it sits for longer than an hour, it has the same hard start problem.
By hard start, I mean it will crank for ~10 seconds before starting. Once it's warm, and is started back up within 5-10mins, it will start within 1-2 seconds of cranking.
Idle will also be slightly rough after starting when cold, but it clears up within 30 seconds.
I've replaced the battery, sparkplugs, and fuel filter.
Is the fuel pressure regulator, the idle air control valve or something else? Is there an easy way to check these before I buy the parts?