Car taking too long to start?
Thread Starter
Almost a Member!
Joined: May 2007
Posts: 28
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From: Florida
2002 C230 Coupe
Car taking too long to start?
Problem is when the engine is cold, the car takes about 5 seconds to start when I have the key turning at the sametime.... Sounds like a starter maybe? My local mech. told me he found no codes malfunctioned.. .And told me that to really know the problem is to find out when it stops starting!
lol Im like great, guess I gotta be stuck in the middle of nowhere now.. Don't really wanna go to the dealer to have them tell me/charge me an arm and a leg for a diagnosis. Any ideas? Car has 63,000 miles is an 02'... No issues with the engine since... Im thinking the key sensors or the sensor with the ignition? 
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Any input would be much appreciated..Thanks!
lol Im like great, guess I gotta be stuck in the middle of nowhere now.. Don't really wanna go to the dealer to have them tell me/charge me an arm and a leg for a diagnosis. Any ideas? Car has 63,000 miles is an 02'... No issues with the engine since... Im thinking the key sensors or the sensor with the ignition? \\Any input would be much appreciated..Thanks!
MBWorld Fanatic!
Joined: Jul 2006
Posts: 2,147
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From: Central Florida
R129, XF Sportbrake, SC400
How old is your battery? I remembered when i changed my battery, the car started much faster, i guess because the battery was supplying more cold cranking amps allowing it to turn faster.
Almost a Member!
Joined: Feb 2008
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From: Chicago IL
02 C240 Black
When you say cold do you mean like outside temp cold or every morning first start with engine cold? Also, is it a slow crank before it fires? Or is a fast strong crank? I concur with Ryan.. I would load test the battery first. If it fails replace it. Knock out the basics first. Some maintenance items could cause this such as a clogged air filter, fuel filter, or fouled plugs, so make sure these things have been done. Then I would verify the fuel pressure is ok. The fuel system is supposed to store a residual amount of fuel pressure after you shut the vehicle off. If the pressure is somehow lost i.e.. residual pressure check valve letting fuel leak back to the tank you will get a long crank start after the vehicle sits for awhile. So I might let it sit over night with a fuel pressure gauge attached to it to see if the pressure drops below spec.
Newbie
Joined: Feb 2008
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2005 C230K
I am having a somewhat similar problem with the car taking 3-5 seconds to start but only after it has been sitting in the hot sun in the afternoon. I can turn it off and it will start right back up but the initial start is slow. My problem does not occur during a cold start in the morning but only during the day after it has been in the sun a few hours. Not sure if this is some kind of "vapor lock" or some other issue.
Junior Member
Joined: Jul 2007
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2005 C230SS 6-speed, 2003 Audi S8, 1970 Camaro SS/RS
Slow Start Solution...
I had the same issue ermtpa had... the first start in a day, or after sitting for a few hours, it took 5-6 seconds until the car would fire. My dealer tech is a good guy, and checked this for me at no charge: he started the car, let it fully pressurize the fuel injection system and then shut it off and immediately tested the rail pressure. Something like 45-50psi. 15 minutes later it was near zero. The injectors were sticking slightly open. He replaced all four injectors under warranty and I haven't had an issue since... that all happened at about 48k miles. I've got 57k on the car now.
