like the warm up regulator/compensator(?). Follow ctaylor's direction. If its starting OK cold, I wouldn't suspect the CSV.

Look into your fuel pressure regulation system (don't know that engine well enough to define that - can somebody chime in?).

Keep us posted - I have two M100 engines (the legendary and scary 6.9) that I will be diving into this spring and both have similar problems. I'll be interested in your findings.

Kevin

__________________
"Dangerous with a wrench...and not smart enough to know it"

Stable (in order of acqusition):
'84 500SL, 280SEL (Euros)
'77 280SE. '90 560SEL
'79 450SEL 6.9,
'95 C280 (totalled by daughter 8/07)
'81 280SL (rescued) '88 300CE
'86 560SEC '95 C36
'01 CL55

DD's: '04 S500 4Matic (SWMBO)
'04 F150 Crew