I'm looking for opinions about my diagnosis.
I've owned a '97 E320 (24 valve straight six) since new. After about 15K
miles it began to have a delayed hot start, specifically, after being
driven for at least 3 miles and parked for a half hour to 4 hours it
cranks but won't start until I step on the gas to open the throttle.
Then it starts with a roar and initially acts like it was "flooded" as
we used to say with carburated engines.
The car has now gone 33K miles and the problem is consistent. The engine
is otherwise very responsive, smooth, good power and good fuel economy.
The spark plugs were changed at 30K miles and I checked the fuel system
pressure regulator - it was fine, no fuel leak into the intake manifold.
My diagnosis is that the injectors are leaking fuel into the intake
ports and the engine is, in fact, being "flooded" after shut down. A
confirming symptom is that when I changed the spark plugs #6 spark plug
was wet with fuel; the others were normal. However, my diagnosis is made
with no knowledge of how the idle speed is controlled and what happens
there when the engine is cranked: i.e. does the idle speed controller
have a "start" position? I don't know and the Bosch fuel injection book
doesn't discuss hot starting.
So I'd appreciate your opinions and ideas.