I would also suggest cleaning the tirgger points for the fuel injection along with the ignition points. Dirt or oil on the ignition points will make for very hard cold starts (do you smell fuel?).

Also inspect for leaking injector lines cold (this means low fuel pressure at the nozzles) along with cold start valve and thermo-time valve.

My 280 starts up instantly if I clean the ingnition point prior to attempting.

Another thing to check is wear in the distributor -- as the bushing at the base wears, the shaft will push off to the passenger side slightly under the pressure of the ignition points. This will prevent old trigger points from opening on the driver's side due to wear on the rubbing block, so you only have four cylinders with fuel, then usually six, and only eight when the dizzy starts to warm up. If you get surging during warmup, for sure this is the case.

New trigger points help, but the real cure is to replace the points with a breakerless system and re-bush the dizzy.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!