This past may i gave my sister my 300E with about 119K on it. In the past
year I replaced and serviced many parts. The car runs great ohter than
having a real hard time starting. It takes about 3 or 4 times and holding
the pedal down all the way. SOmeone told me it could be the fuel pressure
regulator.....? Anyone else have any idea what it could be? Thanks,
Charlie, Monmouth County NJ
IMHO the fuel pressure is probably OK because the problem only occurs at
Fuel injected engines have a "cold start system" that injects additional
fuel into the engine for a very short time during cold starts - five to
fifteen seconds to help get them started and for initial warm-up.
Basically, there's an engine temperature sensor: ON below a certain
temperature and OFF above it.
A relay that's ON longer as the temperature is lower.
And an electric cold start valve: ON injects fuel, OFF cuts off the fuel.
One of these isn't doing what it should be.
i dont think any smoke, when i mean hard starting, i mean realy really hard
starting....you turn that key and you have to hold it over for a long time
and keep on stomping down on the pedal- thanks tg and00 for your help so
Glad you mentioned this.I have 91 560SEC that takes 2 to 3 long cranks
to start and there is a black smoke when it starts up. No problem
starting cold though. Have not figured the cause for this yet.
Well, black smoke is usually unburned fuel, so that's probably just a
secondary symptom of whatever's making your car hard to start when
hot, rather than a separate problem.
I had some hot-starting problems on my 250C as well, but narrowed it
down to the fact that I was using a new electronic distributor with
the original stock coil. After installing an MSD coil and ignition
control box, and widening the gaps on the spark plugs, the problem
Is everything stock in your engine? If your timing is set correctly,
and you have good engine vacuum, I'd have a tech look at your ignition
system. You coil may be starting to go, and becoming weaker when hot.
"The most fundamental law of wartime negotiations; you negotiate with the enemy
What about white smoke, coming out from the engine compartment and
tailpipe ONLY after the car sits for a couple days without being
started? It takes about 10 minutes to get it started, then it misses
for about 20 mmiles of driving, then it runs great?
It comes from the engine compartment AND the tailpipe?
This could be bad. Perhaps a leaking head gasket that is losing
coolant both internally and externally. Keep an eye on coolant level
and also check the oil and coolant for any strange appearance.
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