I've searched already. I hope you guys can help me...

Two days ago, my 2000 S4 didn't want to start in the (cold) morning. After about 8 attempts, it DID catch, and ran fine - as long as the engine is warm. I was thinking the MAF sensor is bad, and replaced mine with a known good one, but it was no help. I did NOT "reset" the ECU - should I? I also read about cheking the vacuum lines to the fuel pressure regulator, but haven't done that yet. I don't have any CELs.

Anything else I should consider?

THANKS!