My 240 DL (130,000 miles) has previously exhibited difficult starting, whether the engine is already hot or cold. When it starts, it initially runs VERY rough and spews lots of smoke out the tailpipe--it appears to be running very rich. After 5 - 10 seconds or so, the excess fuel burns off and I can get the engine to rev strongly and smoothly. It also exhibits idle "surging" from time to time or idle that is unstable, sometimes going up and down. This idle instability seems unrelated to whether the car was hard to start that day or not...

Recently things got worse. Got in one morning when the engine was "cold" and it just would not start at all, not even one combustion sputter-just like there was no spark. (I live in S. Cal., so "cold" means 60 degrees F.) Smelled lots of unburned gas at the tailpipe. Waited 3 hours and then it just started perfectly like nothing at all was wrong.

Brought it to a shop and they diagnosed as having a faulty fuel pressure regulator. I replaced it, and there was no improvement. I have checked the spark during the times it won't start and it is very strong, so the ignition is OK. Pulled a plug during same time and found it to be wet with gas, of course.

HELP! What could be causing this flooding???