C280 will not start

[estrellajon]

I have a 94 C280 where my car has an inconsistent starting problem. If the car starts, the car runs normally with no apparent problem signs. On other occasions, the car will not start but shows signs of wanting too. After a few minutes, it would start. Doing some searches on different forums I seem to have narrowed it down to these probable causes.. In addition, there are no codes present.

Fuel Pump
Fuel filter
Fuel Pump Relay
Crankshaft Position Sensor or Camshaft Position Sensor. What's the difference if any?

Does anyone have any experience with similar issues. Where are these items located?

[zzDragonzz]

when you start the car and let it warm up will it die on you out of no where? Or when you drive the car will it die on you at a stop light? If this happens it is the crank piece of shit sensor.

Or will it just not start up at all at times like in the morning (first start)?

[estrellajon]

Originally posted by zzDragonzz
when you start the car and let it warm up will it die on you out of no where? Or when you drive the car will it die on you at a stop light? If this happens it is the crank piece of shit sensor.

Or will it just not start up at all at times like in the morning (first start)?


If the car starts, it runs fine. Its the initial starting procedure. It's inconsistent. I was driving it fine then when I parked it for 2 minutes, then it wont start. I had to wait a few minutes before it started again. Then 2 days later, the next day, this time a cold start.....it won't start. Again had to wait a few minutes before I could start it again. Is this an indication of the Crank Position Sensor or more of a fuel delivery issue like, fuel relay, fuel filter or fuel pump? :confused:

[zzDragonzz]

sounds like the CPS is going out on you, I had this similar problem prior to it failing completely...

[SLAMMED_C]

Originally posted by estrellajon
I have a 94 C280 where my car has an inconsistent starting problem. If the car starts, the car runs normally with no apparent problem signs. On other occasions, the car will not start but shows signs of wanting too. After a few minutes, it would start. Doing some searches on different forums I seem to have narrowed it down to these probable causes.. In addition, there are no codes present.

Fuel Pump
Fuel filter
Fuel Pump Relay
Crankshaft Position Sensor or Camshaft Position Sensor. What's the difference if any?

Does anyone have any experience with similar issues. Where are these items located?
so when your car does not start.. it still cranks?
it could be the crank sensor... you will not have any stored codes for a crank sensor. the only way to see it it to have the code retriever hooked up and while you start it,o nly then will it set a fault.. but will vanish as soon as you stop cranking.
also you should hook up a fuel pressure gauge and just monitor fuel pressure to see if it is non existant for those times when it doesnt want to start.
maybe also swap the relay for the fuel pump with another one.

you have no codes at all for anything?

[estrellajon]

Originally posted by SLAMMED_C
so when your car does not start.. it still cranks?
it could be the crank sensor... you will not have any stored codes for a crank sensor. the only way to see it it to have the code retriever hooked up and while you start it,o nly then will it set a fault.. but will vanish as soon as you stop cranking.
also you should hook up a fuel pressure gauge and just monitor fuel pressure to see if it is non existant for those times when it doesnt want to start.
maybe also swap the relay for the fuel pump with another one.

you have no codes at all for anything?

No codes at all. The car still cranks and eventually will start after a few minutes. where is the fuel pump relay? Does this relay normally go bad? I'll try hooking up the code reader when cranking. What error code is specific to the CPS? How do I replace the CPS if thats what it is?

[jnolte]

i think the fuel pump relay is in the trunk, its a fuse near the battery. ITs a big fuse not a small one next to the fuse box

[estrellajon]

Originally posted by jnolte
i think the fuel pump relay is in the trunk, its a fuse near the battery. ITs a big fuse not a small one next to the fuse box

Will the symptoms I described be similar to a CPS problem?

[jnenad16]

first of all, do you hear the fuel pump when you turn the key? if so, you can skip the fuel pump and fuel relay. next, you need to hook up the fuel pressure gauge to the fuel rail and see if there is enough pressure when you crank(around 3.5bar or 50psi). if all of these check out, you are looking at an ignition malfunction. then you can turn your attention towards the crank or cam sensors. however, never overlook the other sensors that the ecu depends on to start, such as the MAS and the CTS. MAS is quite easy to diagnose, but the CTS is a bit more complicated if you are not familiar with its funtion.
every engine needs four things to start and run:fuel, spark, compression, correct timing.

nenad

[estrellajon]

Originally posted by jnenad16
first of all, do you hear the fuel pump when you turn the key? if so, you can skip the fuel pump and fuel relay. next, you need to hook up the fuel pressure gauge to the fuel rail and see if there is enough pressure when you crank(around 3.5bar or 50psi). if all of these check out, you are looking at an ignition malfunction. then you can turn your attention towards the crank or cam sensors. however, never overlook the other sensors that the ecu depends on to start, such as the MAS and the CTS. MAS is quite easy to diagnose, but the CTS is a bit more complicated if you are not familiar with its funtion.
every engine needs four things to start and run:fuel, spark, compression, correct timing.

nenad

What is a CTS? Yeah, I hear a whine what I turn the key and I'm assuming thats the fuel pump. How do I go about connecting a fuel pressure guage on the fuel rail? My MAS is new so I know its not that and I have experienced a failing MAS.

I just had all my engine and transmission mounts done last week costing $800 after I did a seach on this site regarding an engine grinding noise. Runs like brand new then this happens, but I'll feel better once I figure out my issue is. Ill attempt to change the fuel filter by process of elimination.

[jnenad16]

ah, so did this happen right after the mounts were replaced? if so, Im guessing they disconnected the ground strap and forgot to reconnect it upon the installation of the mounts.
CTS is a coolant temperature sensor. its the one on top of the water pump, usually with a four prong/pin connector. either the sensor has no continuity or the connector is loosely connected.
the fuel pressure can be checked by connecting the pressure gauge to the service port on the fuel rail. you'll see a metal cap, like a valve stem cap, but larger, next to the black plastic cover thats next to the valve cover.

nenad

[estrellajon]

Originally posted by jnenad16
ah, so did this happen right after the mounts were replaced? if so, Im guessing they disconnected the ground strap and forgot to reconnect it upon the installation of the mounts.
CTS is a coolant temperature sensor. its the one on top of the water pump, usually with a four prong/pin connector. either the sensor has no continuity or the connector is loosely connected.
the fuel pressure can be checked by connecting the pressure gauge to the service port on the fuel rail. you'll see a metal cap, like a valve stem cap, but larger, next to the black plastic cover thats next to the valve cover.

nenad

Sorry for the late reply nenad. But soon after this thread, my tranny went out on me. I was quoted $5k. So I initially decided to either sell or donate the car. But I found a used tranny online with 35K miles for $500 then $700 labor to remove and replace the old tranny and may go this route.

That said, once I get my car back, I'm back with the initial starting problem. :rolleyes: I wonder if I should go ahead and try to replace the CPS or should a shop diagnose it further. I've done so much work on this car and resolving these will make it perfect again. At least for a bit.

Some people on this thread experience different symptoms like car dying while the engine is running. My symptom is really the initial start. Oh....and another thing I noticed. When I turn the engine off, there is a long high pitched whine which I never noticed before. What could that be. Will that be related to my starting problem?

[94benZo]

I've got a 94 c280 also.. its doing the same thing, but usually if i give it a little gas while trying to start, it'll start. I've changed the fuel filter, MAS, spark plugs but the problem still there... it won't do it all the time, just enough to annoy me. And there's no code either... by the way, how many miles does your tranny has when it went out?

[estrellajon]

Originally posted by 94benZo
I've got a 94 c280 also.. its doing the same thing, but usually if i give it a little gas while trying to start, it'll start. I've changed the fuel filter, MAS, spark plugs but the problem still there... it won't do it all the time, just enough to annoy me. And there's no code either... by the way, how many miles does your tranny has when it went out?

funny that you mentioned this but I just responded to a different thread who's having tranny problems. This was my quote on that trhread.

"I tell you what. I was in a similar situation you were 2 weeks ago. My tranny stopped working and starting to grind a little bit. I took it to my trusted mechanic who specializes on MB's. He told me I need a new tranny which would be $5k. I said forget it, I'll just donate my car since its not worth it. So I decided to call Aamco transmission since they specialize in all types of transmissions and they told me that 90% of transmission problem does need a new on but a single part or two. And they said that from their experience, MB trannies or built well and only certain pieces go bad. So I bit the bullet and put my trust in them. They replaced parts that looked worn which came out to $200 and labor was $300. But it was a lot better than the initial quote of $5k for just replacing the whole tranny. Now the car runs brand new. Shop around for several diagnosis before giving up."

But my starting problem still exist.:rolleyes: I may try what I found on doing a search which was majority a CPS problem. I was guessing it may also be a fuel pump but the symptoms are totally different than what I'm experiencing. I'll replace the CPS and repost.

[ship]

ok first off, when it does start is there an extended crank?? like more than normal for your car??

and changing your fuel filter is always a good idea btw, i do it every third oil change with my air filter, that's just me, but always cheaper to maintain than fix, and there is a lot of crap in the gas down here.

if you hear a noise when key is engaged your fuel pump sounds like it's working.. but that's not an accurate test

you can always test it by doing a pressure and volume test at the rail..
the engine should also allow fuel when the engine cranks enough to build oil pressure and it sends fuel then, hence the long crank question..

and the crank and cam sensors tell the computer where the valves are in position to the pistons.. both very important to starting and running..

but all the sensors ive seen throw codes.... and why have you ruled out everything else? just asking

[estrellajon]

Originally posted by ship
ok first off, when it does start is there an extended crank?? like more than normal for your car??

and changing your fuel filter is always a good idea btw, i do it every third oil change with my air filter, that's just me, but always cheaper to maintain than fix, and there is a lot of crap in the gas down here.

if you hear a noise when key is engaged your fuel pump sounds like it's working.. but that's not an accurate test

you can always test it by doing a pressure and volume test at the rail..
the engine should also allow fuel when the engine cranks enough to build oil pressure and it sends fuel then, hence the long crank question..

and the crank and cam sensors tell the computer where the valves are in position to the pistons.. both very important to starting and running..

but all the sensors ive seen throw codes.... and why have you ruled out everything else? just asking

I'm not ruling out everything else since all of the above could be the culprit. I'm just narrowing it down to the most possible from all the searches I've done on this forum and others. You're right, additional diagnostics needs to be done before pin pointing the problem. At this point, my car wont start at all and I'm having it diagnosed by a mechanic to pinpoint the issue.

[estrellajon]

UPDATE: after all this, the reason was the fuel pump relay. $40

[poppagiorgio]

Where would I find the Crank Position Sensor on a 2000 C280? And where was the relay in the trunk?

[99c43]

Apparently this isn't a rarity. Just got back from the dealer, and apparently in the state of California, or maybe in Southern California, or just maybe at Hoehn Mercedes in Carlsbad they have what is called "Fair Market Price" on SERVICE. I know this part is relatively easy to install (I am talking about the Crankshaft POS Sensor) and the dealer wanted to charge me 3.3 hours labor, and 120.00 for the part. (The service manager told me that book time is .8 hours, the extra time added was the FMV price of service),The labor charge here is 120.00. So you can do the math. But it was two grips of cash to fix. I professionally let them know that I wasn't at all amused by the charges. SO:

I didn't have them do it. Luckily enough the car had been sitting for an hour or so while I pleaded my case to them that this is robbery, I left there without paying the Diagnostic Fee of 120.00, so that was good.

I ordered the part from autohausaz for 80.00, should arrive by Thursday. I'll install myself....

Oh, same symptom, we have been having a heat wave here and after a short stop on Sunday the car didn't start. Called the tow truck, told to wait patiently in the 102 degree heat, of which my black C43 was adding another 20 degress I am sure to my heat index. And after telling me that it would take about 90 minutes for the tow truck to get there I had nothing to do but wait. Perhaps the tow place was busy picking up Benz's with CPS problems. Well about an hour into the wait I turned the key and wooohoo it started. Then it happened again, and again, logged into this forum and found that I am not the only one.

Just wanted to add to the I've been duped by these faulty CPS's

[zzDragonzz]

YAY we have another one!!!! How is your gas mileage by the way?

[99c43]

Originally posted by zzDragonzz
YAY we have another one!!!! How is your gas mileage by the way?

I guess in this instance "misery loves company"

I am avg. around 21mpg or so mixed city/hwy. I rarely drop it to the floor so I think that is what keeps my mileage somewhat manageable. I have heard that some people are only getting about 220 miles before the red light goes on. I am consistently getting 300-305 before it goes on.

OK, here is my question. As I really like to understand what it is that is going on with any of my cars.

Does anyone know why this CPS is failing? It would seem that it has something to do with the heat. I have no problem with a cold start, and apparently no one else does. Is there a more robust alternative to the stock sensor? Is there a way to bypass the sensor altogether? IF this is an option could it be catastrophic?

sdh

[Proven Guilty]

off topic:

i'm in carlsbad every day. i car pool with my boss who's also my best friend, and he's right off carlsbad village drive and highland :)

good to know there is a dealer down here, i haven't had time to look it up. i used to live in costa mesa up in orange county, and got everything from fletcher jones (where the car was originally purchased).

[99c43]

Originally posted by Proven Guilty
off topic:

i'm in carlsbad every day. i car pool with my boss who's also my best friend, and he's right off carlsbad village drive and highland :)

good to know there is a dealer down here, i haven't had time to look it up. i used to live in costa mesa up in orange county, and got everything from fletcher jones (where the car was originally purchased).

I got another alternative for you then. Right off Carlsbad Village and Roosevelt (by the Pizza Port Brewery) there is a Mercedes Independant that I use "most" of the time. He didn't have any openings this week hence the reason I had to use the dealership. Anyway the owners name is John, and he is a fantastic individual to deal with, honesty and integrity are two words to describe him and his business ethic. His number is 760-434-1348. I imagine if your car is still under warranty you would want to use Hoehn, but as soon as it is out. I would hightly recommend the Indie..

[Proven Guilty]

Originally posted by 99c43
I got another alternative for you then. Right off Carlsbad Village and Roosevelt (by the Pizza Port Brewery) there is a Mercedes Independant that I use "most" of the time. He didn't have any openings this week hence the reason I had to use the dealership. Anyway the owners name is John, and he is a fantastic individual to deal with, honesty and integrity are two words to describe him and his business ethic. His number is 760-434-1348. I imagine if your car is still under warranty you would want to use Hoehn, but as soon as it is out. I would hightly recommend the Indie..

AWESOME! there is a guy i trust in costa mesa named john at coast MBZ. he hooked me up with a shop the rebuilt my tranny since i wanted it stronger to handle much more horsepower (c230 kompressor that i was looking to get 265rwhp with perforance upgrades and nitrous express). right now its still covered under the extended warranty i purchased with the car when i picked it up used in huntington beach, so i wanna get everything looked over. (CEL is on right now, and it goes into limp mode). i'm suspecting oxygen sensor(s), but john in costa mesa suggested it may be a supercharger related relay; says the magnetic clutch isint engaging/disengaging properly.

i had such high hopes for this car, but i lost all motivation with it after an accident back in march while i was commuting back home from work in chicago (i was living in detroit, MI). to make a long story short: it was icy, and some prick was doing 90mph over black ice, lost control, and crashed into the passenger side quarter panel. mercury insurance cancelled me 2 days before the accidnet because there was problems with my payment, and they never forwarded to michigan like i requested, so i was unaware and unable to correct the problem (mercury only bills bi-monthly). its an ongoing legal battle, and i just dont have out-of-pocket cash to dick around with it anymore.

any suggestions for a good body shop? maybe there's hope after all! :D

zzdragonzz: while mine may not be a c43, i get 24mpg if i romp on it 24/7 with a c230k. long distance trips i get every bit of 29-30ish mpg and i'm not nice on my cars :)


Originally posted by ship:and the crank and cam sensors tell the computer where the valves are in position to the pistons.. both very important to starting and running.. with that being said, my educated guess would suggest it could be detrimental in the event of a timing chain/belt failure (not sure what these cars run, i'm assuming a chain). seems like with the car relying on these to determine valve position/crank position/camshaft position etc its probably feeding back to the ECU and working with a network of other sensors. i don't see how it would be possible to eliminate it.

[99c43]

Originally posted by Proven Guilty

any suggestions for a good body shop? maybe there's hope after all! :D

with that being said, my educated guess would suggest it could be detrimental in the event of a timing chain/belt failure (not sure what these cars run, i'm assuming a chain). seems like with the car relying on these to determine valve position/crank position/camshaft position etc its probably feeding back to the ECU and working with a network of other sensors. i don't see how it would be possible to eliminate it.

Yes indeed, I do have a recommendation, BTW I am not affiliated with the Indie or the Body Shop I am recommending. I have a custom Z32 that I used to show a while back and every time I would need some cosmetic touch ups or whatever, I would bring it to Rancho Auto Body in Encinitas. James is the owners name and he has been in business for about 3 decades. Does a great job. His number is 760-942-4213.

It is frustrating on that sensor. I can't believe how many people just on mercedes boards are having the problem, much less those that aren't on the boards. A more robust sensor is in order for sure.

[Proven Guilty]

the only things i've been trully dissapointed with on these cars are the MAF/MAS and the CPS sensors. with as common of an issue as it is; should have been a recall because they're quite spendy to fix.

A common issue with the MAF though is if you have a K&N drop-in filter, be weary of how much oil is used when "servicing" and cleaning the air filter. using too much can foul the MAF very very easily.

The CPS is a common-fail item however, much like an O2 sensor. I don't think there is any way around it with a fuel injection system that is emissions concious :o

oh, one last thing - any name dropping i can do so i can let him know you recommended me to him? he might appreciate it, and help you out the next time you need some work done- cause the stuff i need done isin't going to be cheap ;)

[99c43]

Originally posted by Proven Guilty

oh, one last thing - any name dropping i can do so i can let him know you recommended me to him? he might appreciate it, and help you out the next time you need some work done- cause the stuff i need done isin't going to be cheap ;)

Sure if you go see John for mechanical repairs you can tell him Scott sent you w/ the C43. I think I am the only one with a C43 that he services....

CPS - So I ordered the part from Autohausaz, I start it up, go to work and then I go to lunch, and the damn thing didn't start again:mad: so I was like F it. The CPS must not be the problem and with no code I didn't know what to do. So when it cooled down off I was to see John. Well on my way there traffic was heavy. And the car stalled on the 5, I am sure I wasn't the only one pissed as I stopped traffic at rush hour. Anyway frantically cranking and cranking and finally about 10 min. later the car started, this time the CEL came on....woo hoo. I thought at the very least they could hook up the diagnostic and tell me WTF is going on. Well to make a long story short. The code came back Crank Pos. Sensor. HMMM, he tells me I must of got a "lemon" part. So he drove me to the dealership, and I picked up an OEM CPS. Same P/N as the Bosch except on one side of it said Mercedes, and the other Bosch. Get back to his shop, and he pops the new one in in about 5 minutes, car started, CEL cleared, and have been driving on it for 4 days now without any problems. All in all the cost was 85.00 for labor and 105.00 for the part. I don't know how often they fail, but I went ahead and bought a second sensor and put it in the glove compartment.....

Good luck with your repairs....

Scott

[!!!!!NJ Drive]

ok, add me to the list...I missed work because my car stalled at a light in the left hand lane during morning traffic on a major roadway (there isnt an icon that quite descrides how i felt/feel). while looking for solutions all morning i realized the is a common cross platform MB problem.

I know where it is, what i need, but just dont understand how to get the old one out & put the new one in....i just dont see where its attached to use the socket wrench at :confused:

[99c43]

Originally posted by !!!!!NJ Drive
ok, add me to the list...I missed work because my car stalled at a light in the left hand lane during morning traffic on a major roadway (there isnt an icon that quite descrides how i felt/feel). while looking for solutions all morning i realized the is a common cross platform MB problem.

I know where it is, what i need, but just dont understand how to get the old one out & put the new one in....i just dont see where its attached to use the socket wrench at :confused:

http://www.autohausaz.com/secure/PartImages/0261210141.jpg

I am going to try and help you out here. I actually had the shop do it for me, with that said. It took him 5 minutes to do the job and I was embarrased that I didn't do it myself with the ease of it. I did watch him though. He simply stood over the drivers side fender and reached his right hand down and pulled the cable from the sensor. Once he pulled the cable he then put the socket on a long extension and pulled out the single screw that held the sensor in place, then reached down and pulled the sensor out. He did this by touch rather than actually looking down and seeing what he was doing. I think once you pull the sensor out, you will see the screw and have to guide the socket on it. Ensure that you are carefull as I have read that some people drop the screw when trying to pull it out. You may want to loosen it and then reach down and attempt to pull it out with your fingers. Ensure the engine is cold when doing this...

Scott

[!!!!!NJ Drive]

finally got it off...only to find out it was the one for my car, there are two kinds #003 153 27 28 its clipped to the wireharness from the side (pass. side)....& 003 153 96 28 which is front and back, like the one shown above

[glenmore]

I'm having the same trouble as the original poster, an intermittent no start. The car will crank but not start. After a start the car drives perfectly. Never happens on the first start of the day. It has been unusually hot out here lately. The car will not restart sometimes after 10 minutes sometimes after 2 hours. If you just wait awhile, it will start. After doing a bit of reading I thought I'd change the CPS. On my 2000 C280, it is just to the right of the oil dipstick above the belt. It is attached with one E8 Torx screw (10Nm torque), so you have to get a set of these sockets. Autozone has a decent set for $17. Check out what the sensor looks like at one of the parts sites. I bought mine at AutoHauz for $78. Take the screw out first and pull out the sensor and then remove the connector. There is a small O ring. As someone mentioned there are two types for specific engine numbers. After I put in the new sensor, the car started and worked fine over the next day with about 10 starts. Then it failed to start after sitting in our garage for 2 hours. It started after just waiting a bit. Battery is fine. I gather that the CPS does not throw a code. Would a failing fuel pump relay throw a code? Possible I got a defective part? It was original Mercedes OEM.

Thanks for any more thoughts,

glenmore
2000 C280
1991 300CE
1990 LS400

[99c43]

Originally posted by !!!!!NJ Drive
finally got it off...only to find out it was the one for my car, there are two kinds #003 153 27 28 its clipped to the wireharness from the side (pass. side)....& 003 153 96 28 which is front and back, like the one shown above

Yep, there are two, I actually bought both from Autohausaz, then returned the other. My car uses the one with dual clips. The other one has a single clip (?)

[99c43]

Originally posted by glenmore
After I put in the new sensor, the car started and worked fine over the next day with about 10 starts. Then it failed to start after sitting in our garage for 2 hours. It started after just waiting a bit. Battery is fine. I gather that the CPS does not throw a code. Would a failing fuel pump relay throw a code? Possible I got a defective part? It was original Mercedes OEM.

Thanks for any more thoughts,

glenmore
2000 C280
1991 300CE
1990 LS400

Well as you may have seen from my post, I too had a similiar experience. I had the part replaced only to have the same problem. I got a lemon part. The resistance property on this sensor changes when it gets hot. I dont' know what the +/- can be until the car doesn't accept it. But out the box the resistance is about 1100 ohms. The "failed" part was at 1300 ohms when pulled from a warm engine, but when left to cool it dropped to 1180 ohms. Can you post what your resistance is between the two connectors?

[!!!!!NJ Drive]

Originally posted by 99c43
Yep, there are two, I actually bought both from Autohausaz, then returned the other. My car uses the one with dual clips. The other one has a single clip (?) yep, mine uses the single clip..just got word they changed the single clip part# i'll update as soon as mine arrives

[glenmore]

Originally posted by 99c43
But out the box the resistance is about 1100 ohms. The "failed" part was at 1300 ohms when pulled from a warm engine, but when left to cool it dropped to 1180 ohms. Can you post what your resistance is between the two connectors?

Please forgive my ignorance, but I don't know how to do this. I have a voltmeter that has 4 sections, DCV, ACV, DCA and OHM. I've set it to ohms and touched the leads to the different prongs on the CPS but there is no reading. How do I measure it?

So far so good for today, no "no starts". I got one suggestion from another board to swap out the fuel pump relay in the trunk. Hopefully I can catch it when there is a no start (it is my wife's car) and I can try and listen for the fuel pump.

Thanks,

glenmore

[OzC36]

Fuel pump relay in the boot (trunk) is the green item next to the fuse box on the right side (see thumbnail below):

http://img19.imageshack.us/img19/2565/dsc02722mp3.th.jpg (http://img19.imageshack.us/my.php?image=dsc02722mp3.jpg)