colinh

I have a 2000 S430. It has trouble starting in the morning, regardless of the temperature. Once it starts, it works great the whole day. This problem stareted three weeks ago after my wife drove the fuel tank to almost empty. Since then, I have starting problem for every two or three days. Based on the tips from other thread, I disconnected the negative terminal of the battery to reset the computer, and that seemed to fix it for a few days. However, it failed to start again this morning. I disconnect the negative terminal one more time and the car started again. Does anybody has any idea about this problem? Is it something else other than resetting the computer? BTW, how do I keep the trunk unlocked all the time? I heard about the 'COMAND', but how do you get to it. Thanks.

Colin

mbtech208

What symptoms does it have when you try to start it? Can you turn the key? Does the engine crank? Does it crank slowly? Does it crank normally, just not start? Does it feel like it "wants" to start but just can't quite catch?

colinh

The car cranks ok. The starter will turn normally, but I don't feel any sparking inside the engine. The starter cranks without any problem. Yesterday, I also noticed that the engine can only run up to 4200 rpm(in neutral) and it started shaking.

The car didn't start again this morning. I disconnected the battery's negative terminal and it still didn't start. I am going to let it sit for several hours and probably it will start again. Once it starts, it works fine for the rest of the day. I sent it to the dealer last week, but the car started every time and I was charged for diagnosis for nothing. Any idea?

Colin

mbtech208

That part is normal, it's the rev limiter kicking in.
The first place I'd look is the fuel delivery system. The first component I'd check is the crankshaft position sensor (CKP). If it's bad, the engine computer can't see the engine cranking, so it won't deliver any fuel. There is even a bulletin for corrosion at the CKP connector. If that's not it, I'd check for poor connections in the fuel pump wiring circuit.

csumt76

Sound to me like you may be bleeding off fuel pressure, I would think the intermittent crank sensor idea would give you some sort of poor running complaint or a check engine light.

Once you get it to start, will it start repeatedly after that? If if starts say three more times directly in a row with no problems, wait a few hours or even over night and then go try to start it again. If it has trouble starting after you let it sit for a long period of time, cycle the key a few times and let the key sit in position two for a few seconds and keep doing that. Then tip start it and see if it starts up. You may need to find something that is leaking, like fuel filter/regulator.

colinh

Once the car starts, it can start more than three times without any problem. It runs well all day until next morning!

I have sent the car to the dealer to check it out. After two days, they finally were able to pin it down. It is the crankshaft position sensor. They are waiting for parts. It should be repaired in a few days. I'll keep your guys posted after the repair. Thank you very much for the suggestions and comments. This is a great forum!!!

Colin

mbtech208

Glad I could help.