Strange problem in starting - PeachParts Mercedes-Benz Forum

shams13 · #1 10-06-2008, 05:45 PM

I drove back from office today on my E240 2004 and everything was fine. After an hour, i cranked the engine, it started for a few second and stalled. Felt like no fuel was being delivered!! after that i tried many times but it never started.

a few hours later, i cranked again and it started that time. everything is fine now.

why was that problem?? anything serious to worry about???

mpolli · #2 10-06-2008, 10:19 PM

Well, on the one hand, if it never does that again then no... but if it does, then yes...

The only clue I get is the one hour. It suggests possibly a "hot soak" problem. Was the car fully warmed up when you parked it (half hour drive or more)? What was the outside temp? Some parts susceptible to hot soak in general are Crank Position Sensors and Coils. But it could be something else. Did you do a search?

This thread might pertain:

E240 stalling problem - engine temperature sensor?

david s poole · #3 10-06-2008, 10:50 PM

that is a textbook syptom for the crankshaft position sensor.

shams13 · #4 10-07-2008, 03:20 AM

Thank you mpolli and david.

yes the car was fully warm, driven for almost an hour. outside temp was 105. besides, i didn't see any warning messages...

so what does the CPS do and why did my car start later??

mpolli · #5 10-07-2008, 04:05 AM

If you know much about cars then you might have noticed something missing under the hood (bonnet?).... The distributor! It has been sent away by the power of the almighty computer. The computer sets the timing not the distributor. But even a computer needs some information to do its job. It needs to know "where is the crank position?". So enter the CPS. That is its job to do. But being made of.... whatever it is made of, it can get tired of being heated up really hot and then cooled down day after day, year after year (well mine seems to like it...). Anyway it is a little bit of electronics that can decide it doesn't like the heat of the kitchen so it wants out. OK call it thermal stress. But once it "cools off" it has a whole new outlook on life. OK call it intermittant. OK call it thermal intermittant. Oh my I have been up too long.... But keep in mind that the other thread ended up with a different problem, a relay module of some kind, so it is not definitely the CPS, just the symptom seems to fit. But it could be something else.

shams13 · #6 10-10-2008, 08:25 AM

hi mpolli

today, the engine was cold and outside temp was 110. i cranked and it started fine, switched off and cranked again, it started the second time as well. but didnt start the third time. same problem occured.

can i be sure of bad cps now?

mpolli · #7 10-10-2008, 01:58 PM

NO! Since the car was cold that does not support the theory. But does not eliminate it either. Could be a fuel relay I suppose or that relay module mentioned in the other thread. Maybe it was a fuel relay module. I would tend to go with what was mentioned in the other thread since they were working on this exact car I think. But I am NOT an expert. You need someone more informed than me to say.

shams13 · #8 10-11-2008, 05:10 AM

thanks mpolli.
do you know where is the fuel relay and relay module. can i check those by myself?

btw my car is diffrent than of the other thread. mine is w211 and the one on the other thread is w210.

shams13 · #9 10-11-2008, 02:33 PM

fixed the problem today. changes the fuel pump and the filter.