wonkaa

EDIT: changed the title of thread for more viewers/advice.
please read the thread but so far, we seem to have ruled out: fuel pump fuse and relay, fuel pump itself, CPS/Crankshaft sensor, and I have tested the batteries. Now thinking about Alternator or i have no idea.. really need to get it scanned but because its stuck at home, its not that easy.


I am just wondering if a faulty Air mass sensor can cause the car to not start..

details:

about 6 months ago the car was diagnosed to have a faulty AMS but i never got around to replacing it. the check engine light was on since but car didnt have any issues until recently.

couple of weeks ago when i went to start the car, i turned the key and the car was ticking over but wouldnt actually start. maybe this lasted 10 seconds, felt like ages so i turned it off. waited a few more seconds and turned the key again and it started fine.

now yesterday i was driving and i felt the car's rev's stuck around 2000-2500 rpm and pushing the accelerator pedal did nothing. the car felt like it was jerky like i was repeatedly tapping on the brakes.

and then i went onto the highway and tried to speed up but it felt as if the car wasnt getting any power. but it came right after a little while and was fine.

i parallel parked it when i reached my destination and turned the car off.

i tried to start it again right after to move the car forward a bit but it cut out immediately. so i did it again and car died again.

i let it be for about 30 minutes and came back. same thing. car wont start.

pressing the accelerator pedal does absolutely nothing to the revs.

car is definitely ticking over, feels like its not getting any fuel or something.



SO... the question is, can the faulty maf/AMS cause this issue or is it something else? because i drove the car fine for 6 months..

could it be... bad fuel pump? blocked fuel lines? some other sensor like crankshaft or camshaft?

car was towed home.. just trying to decide where to take it, but it would be good if i knew what i was dealing with..

appreciate any help.

cm60k

You may have problem with a bad CPS/starting relay/fuel pump..!,

did you try to diagnose the car..?, it will helps to narrow the issue without spending $$$, with less time..

ZAYED,,

wonkaa

i dont have access to a scanner unless i take the car to a workshop.

ive done my best but tbh im not that mechanically inclined so... not too sure

whats a CPS? **EDIT** crankshaft position sensor. if this was the culprit, any way i can find out?

because the accelerator pedal is not doing anything i was assuming maybe there is no fuel being delivered but its just a guess at best.

what are some things i can try at home?

i am planning to order a new air mass sensor which is about $150 USD to get it shipped to me. might take a week to arrive though.

wjcandee

It's $142 from Amazon with free prime shipping (get it from Amazon itself not a vendor so you know it's genuine), the Bosch one. So I don't know what you're getting and from where.

Yes it can cause problems, so can a million other things. Why not just go to a mechanic who works on Mercedes and stop trying to diagnose it yourself, especially if you're "not very handy".

Thank god for annual inspection requirements, or people wouldn't fix their emissions systems and would instead run with the check engine light on until the car fails. Maybe I'm just finicky about having my thing work right and not poisoning others.

wonkaa

well i live in New Zealand. cheapest i found was $158USD which is fine with me.

when i first got the Air Mass Sensor problem 6 months ago, i went through like 3 different
"mb specialists" who couldnt find the problem. i ended up getting it properly diagnosed at the local dealership but they quoted $1400 NZD to replace a AMS!!

I am more than able to follow instructions for diagnosis.

I have mechanical warranty which requires me to get a full service every year or 15000kms. i do an oil change at this time and i also do another oil change in between changes so its around 7-8000kms.

i was assured at the dealership that the faulty AMS wont cause any further problems to my car (but i should get it changed sooner rather than later, which i didnt do due to laziness and the hassle of importing parts from overseas)

anyways... yea

wjcandee

Apologies. I should have realized you were outside the United States. If you can get it in new zealand for 150 bucks, you are an amazing parts finder. :-) and it sounds like you are on it. I hope it's just the MAF sensor, but I suspect it might be something else as well, which really only a decent mechanic can tell you. There are some chains in the United States that everyone on this forum would say one should never go to because they don't know anything about Mercedes, but the fact is that they do generally a pretty good job diagnosing and fixing stuff, and they can't bring themselves to charge the kind of money that MB experts and dealerships charge. So when that approach works, it's not a bad one. And when it fails, there isn't a lot of harm they can do. I don't know if you have generalist chains of auto parts and auto repair, but unless they flee when you drive in in the Mercedes, you might give them a try. Yes Mercedes has some very interesting and specifically engineered aspects, but it also has some very typical engine issues and components.

wonkaa

yep. sometimes i wish i was in the states but o well.

first thing i did was take off the engine covers and remove the MAF completely then tried to start the car. the flap opened up as normal but the symptoms are the same. no go.

its $158 usd which converts to roughly 220nzd which is fine. i was quoted 1400nzd at the local stealers for the same part.

general garage/workshops are really bad. like REAL bad.

the mercedes specialists are usually pretty onto it guys but because NZ is such a small country, rare problems leave them stumped for answers.

I am thinking about buying a scanner when i order the MAF. havent looked for it yet but are there any decent scanners for not too much money? yes, i know that more u pay, the better it would be.. but all i really need is to scan for error codes and i can post it up here then someone would probably be able to shed some light as to which part is faulty. Then i can order the faulty part and eitehr fit it myself or take the car with the part to the mercedes specialists and just pay for the labour.

thanks

cm60k

I don't think MAF sensor can cause the car not starting.!, it's soo weird if it the reason,

starting always refers to "CPS/start motor/starting relay/alternator/alternator regulator/fuel pump/fuel pump relay",,

prefer to diagnose the car before spending $$$..!

ZAYED,,

wonkaa

thats what i thought..

well the car is turning over so i dont think its the starter motor or alternator etc

my best guess is fuel pump related because flooring the accelerator pedal does NOTHING.

cm60k

it's better if you can check the fuel pump fuse & relay first, one of them could damage..?

ZAYED,,

ibeforreal

It may possibly be the accelerator pedal assembly.

wonkaa

if it was, why would the car not start up?

cm60k

I think you're right, pedal acc. sensor doesn't make the car not starting..!

did you check fuel pump fuse & relay..?

ZAYED,,

wonkaa

fuse is good. the relay has some white stuff on two of the pins.

i am going to the stealers to pay NZ$35 for a new one... even though its only US$6.35 i cant be bothered waiting 1 week for shipping.

if its not it, i might try to do a sneaky refund..

i had a look at the Crankshaft sensor (CPS) and found that its US$36.71 and at the local dealers its NZ$140 so like US$100..

might give that a go next if its not the fuel pump relay.

cm60k

Fully Agree,

Most most common starting failure are "CPS/fuel pump/fuse/relay"..!

did you check if fuel pump delivering fuel to the fuel rail..?

ZAYED,,

wonkaa

how can i check if the fuel pump is delivering fuel?

cm60k

You can pull-out the fuel hose from fuel rail, switch the ignition to position 2 without starting, and see if there is some fuel reach to the hose,,

if not, let anyone to starting the car and see if fuel comes-out from the hose..!

ZAYED,,

wonkaa

replacing the relay did nothing.

i will be checking the fuel later on today but im thinking whether its worth it to spend the NZ$140 on a new CPS and trying it out. because if that doesnt solve the problem im already $40+140 out of pocket and left thinking maybe i should have just taken it to the mechanics.

not much chance in onselling the part here in NZ because its such a small country.

should i gamble on it being the CPS? what are the other possibilities..? thanks again

ibeforreal

Symptoms of these cars cutting off and not starting back up immediately is a bad CPS. Once the car cuts off because of a CPS the temperature of the car has to drop to around 80 degrees F before the car will start back up. The CPS here in the US is relatively inexpensive (usually under $50). I always carry a spare one in my car.

Also, if the car starts but stutters or seems like it's going to cut off then I would suggest that it is a MAF related issue. Before purchasing a new one I would buy a can of CRC Mass Air Flow cleaner and try cleaning. Just remove the MAF from the car and spray the you know what out of it with the cleaner. It dries up really quickly. Do not use any hard chemicals like brake cleaner because it will destroy the electronics in the MAF. If you do have to purchase a new MAF don't settle for anything other than the BOSCH brand. Any of the others will only cause you more grief.

When he states that the accelerator doesn't do anything that is classic gas pedal failure. You have to remember that these cars have electronic accelerators and they do fail.

cm60k

After checking fuel delivery, i'm highly recommended to replace the CPS, it's directly send the signal to the ECU for starting over the crank wheel..!

1)
2)
ZAYED,,

wonkaa

ok, i know i have a bad MAF. but its been like that for 6 months

what i want to know is, if i was to replace the CPS, does that explain why the gas pedal does nothing?

i mean normally, when trying to start up a car that doesnt want to start, you can give it some gas/push the accelerator pedal to help it out? u know what i mean? but in my case, it does nothing.


im living in nz and the temperature here is about 30degrees celcius. today is a bit less maybe 25 im not sure.

any chance of a part number for the gas pedal problem? but this problem alone doesnt seem like enough to cause the car not to start.

and what is the likelyhood that the CPS and the pedal both fail?

cm60k

CPS got a magnet/sensor to monitoring the engine’s multiple components & speed of crankshaft rotation via ECU, also it's monitors the engine valves/piston to observes overall engine function,

when this magnet goes weak or not constantly working, the ECU detect that and not allows the Engine to start, for safety reason during to the wrongly signal to tha ECU for crank rotation,,


but as i know; when pedal sensor went away, no problem with starting, will get a little hesitation with no power on idle especially when making full throttle, just my IMO...

ZAYED,,

cm60k

There are around "6" different part #s of W211 E350 pedal sensor, should to get the correct one via your VIN #..!



ZAYED,,

ibeforreal

Read this thread:
http://www.benzworld.org/forums/w210...e-pedal-2.html

And this one (particularly #6)
http://www.benzworld.org/forums/w211...le-issues.html

cm60k

John,

This acc. sensor for (97>>2002) M112/M113 Engines, and it's located in the Engine bay front of brake booster,

after 2003 MB replace it as a part of pedal control,,

see above ^photo^ which i posted.

ZAYED,,