Hard starting..WTF ?
Thread Starter
MBWorld Fanatic!
Joined: Apr 2006
Posts: 1,046
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From: Chicago
04 E55
Hard starting..WTF ?
Happened 2 or 3 times cold in the past 2 weeks...today it's happened twice while it was at or near operating temp. Press the shifter button to start and it cranks until either it times out (once) or starts on the very last revolution before timeout !!! Damn...time for a run to the dealer...any ideas out there ? Fuel pump ? No issues on the MFD and no CEL
Super Member
Joined: Aug 2005
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Sounds like you may be losing fuel pressure when the car is sitting. Possibly due to a faulty fuel pump check valve, which is allowing fuel to bleed back into the tank. Or possibly an almost-plugged fuel filter. Are you running fuel with a high methanol content? That can sometimes cause hard-start problems. Or it could be something else.
Thread Starter
MBWorld Fanatic!
Joined: Apr 2006
Posts: 1,046
Likes: 0
From: Chicago
04 E55
Couple different loads of fuel in the past 2 weeks...I'm sure they all contain methanol but not sure what %. My thought was loss of pressure. After first time I made sure I turned on the ignition and waited a few seconds before I started it and it seemed to start right up. It didn't help another time. It was hot and nasty here today and after lunch the car sat 4 hours so it neer cooled off but sure enough..it timed out on me. Would a situation like this set a code you think ?
Super Member
Joined: Aug 2005
Posts: 665
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Your key-on-but-don't crank test might not be valid. Some cars don't activate the fuel pump unless the engine is running or during cranking - not sure about yours. There might be a warning code set that doesn't illuminate the CEL. You'll have to hook up a scanner to see. More than likely it will show up in Star. Get thee to a dealer.
