Paul,

The injectors were suspect at one point in time, before Peter did the compression checks at school in their shop. I pulled the number one injector, and with the car running on the other cylinders, looked at the "spray" pattern. It was not detectable, visually, but holding the injector horizontally with a paper towel under and in front of the nozzle, expecting to catch the spray, it dripped on the towel directly under the nozzle.

The number two injector was the same. Art noted when he got it back together the idle is a little unstable when it is cold, but smooths out when it warms up enough to warm the intake manifold. He noted this is common with worn out injectors as the initial start up conditions result in poor atomization/evaporation of the fuel. As the engine warms up even the dribbling fuel gets evaporated off the intake manifold surfaces and makes it into the engine, approximately in the same quantity that was originally intended, just not quite as thoroughly mixed. Art noted with new injectors we should expect better fuel economy and response.

Art also suggested using Techron to make sure the deposits left by the evaporating fuel are minimized. Apparently the fuel contains some dissolved additives that are left behind when the liquid is allowed to evaporate off the interior surfaces of the intake manifold instead of being carried with the airflow directly into the combustion chamber.

A number of years ago this was a major problem for CIS type fuel injected engines. The deposits would collect on the intake valves adding to the unfavorable initial start up conditions causing rough idling, hard starting and stalling. The cure for this in the old days was to walnut shell blast the intake valves, usually "in-situ" until Chevron developed the Techron additive.

So, new fuel injectors will be next on the list, followed by lots of other stuff. Good to see my son taking a great interest in keeping this car alive. He seems to really appreciate how unique it is and how much fun it can be. And thanks to everyone for their interest and help through this repair. It was fun sharing some of what we learned and experienced with all of you. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)