I have a 2000 CLK 320 that will sometimes start and sometimes will not start. Seems after the car is warm and you turn it off, it will not start up again. The motor cranks but will not fire up. Leave it over night and it starts right back up again. Could go a couple of days and the samething happens again. Any help would be greatly appreciated. Thanks

 

I assume no messages on the instrument cluster? That's sounds like a bad Crank Position Sensor.

 

no messages.

 

you might wanna ask the people in the w208 forums the w209 is from 2003-2009. They might be more familiar with this problem

 

Its time to trade in your W208 for a W209.

 

Thanks for the help. I will search the 208 section.

 

Regardless of which vehicle it's in, it's the same 3.2L V6 and the symptom sounds just like CPS failure.

 

I replaced the CPS but it did not help. One thing that is different from other CPS problems is that my car does not just stop running. My car seems to not want to start after it gets warm. After driving for about 30 mins, if you stop and turn off the car, it will not start. It just cranks over with no start. After, 24 hours, it cranks right up. Don't know what to do. Any help would be appreciated. Thanks

 

This is a really long shot here and I am going to reference another car... On another car I had it did the same thing, it was the ECU. When it got hot the car would not re-start, something on the board (ignition module) was affected. After it cooled down it worked. Im sure your issue is far simpler but I though I would throw it out there.

 

What is ECU?

 

The computer

 

ECU = Engine Control Unit

Search for Reset ECU and you will find the way to reset the ECU.

 

I have seen the cam sensor cause this problem but not as Often as the crank sensor

 

I had to change my crank sensor on Dec-2008.

My experience was the car would start but would die after a few minutes while running. It would crank but not start. Then after 10 minutes, the car would start and die after a few minutes. The cycle repeated itself. I had to call roadside assistance and the guy changed the crank sensor in 10 minutes.

 

My car never dies while running. It just dies after you turn it off, leave for a few mins, return and try and start it up. Then it just turn over and never fires up. Leave it for 8 or more hours and then it will start up. Fuel pump was replaced during the summer. What do think about fuel filter. My mech did not replace it.

 

Did you ever change the fuel filter? I have changed mine twice already; every 100,000 KM.

 

no. I will try that and report back. Thanks

 

Since you car is 2000 model year, it is time to change the fuel filter.

However, I'm not sure if your issue is related to fuel. Seems like you car can do "cold start" but not "hot start".

 

The crank position sensor actually doesn't sense the "position" of the crankshaft. It's purpose is really just to tell the ECU that the engine is actually rotating. If the CPS doesn't provide a signal, then the ECU assumes the engine has stopped rotating and therefore it does a fuel and spark shut-off. This generally does not throw an error code because the ECU assumes the engine was stopped "on purpose". The same holds true when starting. if the CPS is not telling the ECU that the engine is rotating via the starter, then it won't provide fuel and spark, and therefore, no "start".

Failure to start or run when the engine is hot, with no error codes, is the classic CPS failure symptom. I am perplexed since the CPS was replaced and it didn't fix the problem. Maybe it's not the CPS that's bad but a wiring harness?

 

Check your battery terminals...the same thing happened to me...one of my battery ports were so corroded that when I took off one of the cables off the port the port came off with it...car would start exactly like what you said, but finally after changing the battery out it was 100%...

Good luck...it's worth a shot...



Angelo

 

And like others said, it could be related to fuel delivery, but the way the problem is intermittent, that would probably throw an error due to a mixture or misfire issue.

 

I am currently dealing with a similar problem, what happen in my case is my car start normally, i reached the first red light, then it died...Started back up again and it did start. Second time i drove my car, same thing except it took 2 min to started back up again, and the engine light came one...The Third time, same thing except it never started again...that was 3 weeks ago...I've been troubleshooting it since and now i am really desperate and don't know what else i can do other than scrap the car...

When we tried to read that error, it said clearly crankshaft position sensor, so first thing i did was to buy a new part and replace it. (My initial CPS was stuck and broke as we tried to take it out so i had to remove the tranny and break the part out ...)
However the car would still not start, the engine light did not clear out, and still said CPS...The dealer thought there was a GAP between the sensor and the Flywheel, but no such thing as a GAP the Sensor is magnetic and it holds on the flywheel as it should...The 2pin Cable that send the signal of the CPS to the ECU is fine...
Using MB star software, we tried to read the RPM by manually spin the engine but 0 RPM came...so we thought the ECU is not getting the signal sent by the CPS, until we discovered while checking the drive authorization, it said Specified value: ''Immobilizer is activated''; Actual Value: ''Immobilizer is activated''...we tried to turn off the Immobolizer but it seems the car is not allowing us to change it...

So in other words, it seems the car is purposely not allowing me starting my own car...

I have no idea why this is happening and above all i have no idea how to fix it...Anyone knows why ? 2001 CLK320

 

Where did you guys buy the CPS - is it a genuine MBZ part or something from eBay? Also, what was the specific error code(s) that you pulled from the ECU? As for manually rotating the engine to check the CPS, I doubt that will work because if the ECU doesn't think the engine is running, it won't supply voltage to the CPS circuit. I am not sure about the "immobilizer is active" message. I think that is normal when the engine is not running.

 

The only ''Error'' we can read of the ECU is crank position sensor, (ERROR: PO335). We really had to dig in the software to find that the Immobilizer is activated, considering the car is purposely putting itself in that mode it does not come as an Error...
I've used 4 CPS in this Car 3 after market parts, 1 from the Dealer...all of them tested as they were supper magnectic and were sticking very strongly on metal...I can feel the sensor sometimes sticking on the flywheel, so i know the sensor does what is suppose to do...No space or gap as the dealer suggested...
As for manually rotating the engine, that was a technique that the Dealer itself did, now i know the are purposely incompetent but not that much lol, I am not sure but i think the CPS circuit gets its power when the Ignition is on, that's how it gets a signal from the CPS then allowing the car to start...if the engine had to be on for the CPS circuit to work, then we would never get faillures from the CPS were the car can't start...and that is a common problem...
I couln't sleep yesterday night so instead i read about the Immobilizer, according to some ppl that specialised in programming keys,It is not normal for the Immobilizer to be on when the ignition is on. Immobilizer is a state that cannot be bypass, it happens when the ECU does not receive the correct code from the Key module, thus it thinks someone is steeling the car, and purposely block the Fuel to the engine...we can measure the fuel pressure to the Engine, and it's not there...When we tried to do a CPS callibration, we got no voltage from the CPS, but i believe it's because the car is stuck in that State and Cut the power from the CPS circuit...I am willing to try reprogramming the key to get the car off that Immobilizer state...hopefully it works...
The only thing i don't get is why the engine light would come on and said CPS, if the Immobilizer is activated...one thing for sure was the Light came one, then the car started one last time and never again...

 

Not only does the CPS have to be magnetic, it has to have power applied so that the Hall Effect sensor works. It sounds like it's not getting power, but that could be the case if the ECU is locked-out due to some other problem (i.e. not communicating with EIS).