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Cls 320cdi 2006 difficult to start

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nub1ru
Posts: 63
Joined: Mon Feb 02, 2026 8:13 pm

Greetings, this occurrence is limited to the morning hours. If the ignition is not cycled twice, it will crank for a duration of 10 seconds. No codes and operates exceptionally well.
nub1ru
Posts: 63
Joined: Mon Feb 02, 2026 8:13 pm

Given that I am in a warm climate, we can eliminate the glow plugs as a factor.
GoodWillHunt
Posts: 61
Joined: Mon Feb 02, 2026 8:37 pm

Examine your injector leak-off to identify which ones are excessively leaking back.
NavemRash4u
Posts: 58
Joined: Mon Feb 02, 2026 9:01 pm

Also inspect the return line O-rings, as fuel may syphon back to the tank overnight.

I experienced two malfunctioning glow plugs, and starting issues were evident even at +15°C. However, the coil light was activated immediately upon startup, indicating an issue with the glow plug.
nub1ru
Posts: 63
Joined: Mon Feb 02, 2026 8:13 pm

I am unclear about how the O-rings on the injector prevent drainage to the tank.
RIVERPLAZAAA
Posts: 63
Joined: Mon Feb 02, 2026 8:42 pm

It does not.
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