I had the same problem with my wife's 96 E300D.

It was a fuel problem. The O-ring between the fuel control unit and the IP was leaking. That allowed air into the fuel line.

I diagnosed it by installing a low pressure electric fuel pump in the fuel supply hose where the hose meets the hard line on the fire wall. Within a few seconds of powering on the pump, I could see the drip and find the leak.

$5 o-ring, 1 hour of my time, and it has not been a problem since.

__________________
Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO