C240 Fuel cutting out

[arorat]

S Reg 1999 C240 – I am having the following problems;

1) The engine starter motor just turns after stopping the car, when its cooled down (10-15 minutes) it starts without a problem – started happening 6 months ago – noted 3 times

2) Yesterday the car cut out when idling in traffic – battery light came on and car died. Engine turned over but would not start – plenty of petrol. Called RAC after 15 minutes of trying, told him it might start as soon as he puts key in – obviously it started. RAC Guy mentioned fuel relay was the problem and was staying open !!!

3) Few days back I though I’d hammer the car in acceleration – C240 Power Wowww – the car would not go anywhere with foot down, it seamed the something was telling the pump not to feed petrol to the engine, after slowing down the car was juddering as if running on 5 cylinders.

The car has done 107000 miles, last service was by Independent dealer, changed plugs, HT leads changed.

Can you help with the above points please. Could you also tell me the relationship of the MAF and the Fuel Relay.

Btw: when I was 17, I had similar problems with my dads Hillman Avenger, I used to take the fuel pipe of the pump and suck the petrol !!!

 

[BlackC55]

I think you may have two issues here.

When was the fuel filter last replaced?

When it does not start can you hear the fuel pump?

The fuel pressure needs to be tested when it cuts out to see if this is the cause.

It may also be a faulty crankshaft sensor.

The air mass and fuel relay have no relationship.

NOTE: MAF is for diesel Air Mass for petrol

 

[arorat]

Thanks

This is useful, I am not sure the role Crankshaft sensor plays, but searching for this does bring up issues related to age & heating. Points on Fuel Pump noted.

The car is booked in with Indi as I was tired of paying Merc rates for a car this old, if I have any probs I will give you a call. I am in Surbiton near the A3, you are about 50 miles !!

 

[brandwooddixon]

If the car starts and runs after it has cooled down then this is most probably the crankshaft sensor. Typically they cause this behaviour as they start to breakdown.

The sensor is used to detect Top Dead Centre of the crank and thus allowing the engine management to time the spark and the fueling.

I had one go on my E430 a year or so back (the engine died on a roundabout - damn they're heavy to steer and stop without any assistance). Called the breakdown people and by the time they arrived the car had cooled enough to start. It died 10 minutes later and ended up being towed to the Dealers (less than half a mile away!)

I don't recolect it being all that expensive to replace.

 

[arorat]

E430 - Nice !!

Car was going in for MOT and repair tomorrow but could not get the CPS from Merc today, anyway booked in for next week now. Part number 0031539528 £71.51 inc Vat from Merc and £67 inc from GSF (not in stock). regardless getting it from Merc.

Tony

 

[BlackC55]

Let us know the outcome

 

[arorat]

Hi Black and Brand

CPS was changed today, at last service Indi did not have cable to clear codes. Cleared today and noted Misfire codes and something about engine going into emergency mode !!! All of which sounds right as before the last service the car showed symptoms of running on 5 cylinders, juddering, stalling when hot, cranking but not starting.

Kick down on A3 worked much better than before but its not immensely powerful but smooth as a V6 can be – Irony is I have an untaxed / unMOTed Honda Blackbird sitting in the garage – the failure of working from home these days

Oh yeah, labour was £45 + vat to fit the CPS, adjust foot brake and take it for MOT (mot extra of course)

Once again, thank you for the kind help.

 

[arorat]

Another request if okay !!

After hard acceleration and coming to a stop on idle the C240 still judders, would you have any thoughts ?

Tony

 

[stevesey]

Had a Crankshaft Sensor Failureon a 98 C240 with 100K today (sound faimiliar).

Car had failed to start when hot last week after being in the garage having the fuel tank drain plug seal replaced (probably dried out being on forecourt for 2 months with almost 0 fuel in the tank, failed when exposed to petrol again). At the time tank we quite empty and I assumed it was air in the lines, or something, filled the car up and thought no more of it.

Anyway was at MB dealers today to get the second key sorted and it died on them - they ran a check and the Crankshaft Sensor showed up. Car started once it had cooled down a bit - I wasn't particularly worried as I replaced both crank and cam sensors on my Vectra and car aways ran (in limp mode, with red light sometimes). So the way home I was thinking about booking it in with the garage I bought it from (easiest as they deal with all the warrantly stuff without me needed to check approved dealers etc - also if the insurance backed warrantly didn't cover anything I've only had the car for 2 weeks so they should sort it out anyway).

Anyway shortly after deciding to book it in ASAP it stalled and wouldn't restart, called AA, called garage, and two, rush hour, hours later delivered it too them on back of AA truck. It had cooled enough to start again - but I tried letting it idle while waiting for the AA and it wouldn't run for more than 3 minutes.

There is a question at the end of this though - I didn't get any red light indicating that there was a fault code I might want to look at. So:

a) Should I get a red light for an intermittent Crankshaft Sensor failure? Or the the light only displayed when the fault is present - which is a bit silly as the engine dies so all the lights come on when you try to restart.

b) Do MB ECUs rely purely on the crankshaft sensor - so dead sensor = dead car. VXs (still Bosch) use the camshaft sensor as a backup - so unless both go engine will still run quite well.

c) Should I get a red light for any intermittent failure - or am I supposed to guess when to plug a fault reader in?

Cheers

Steve

 

[television]

If the crankshaft goes open circuit, the engine would stop and the dashboard lights will all come on just as though you had put the key in to start the car, the reason being that the ign is on but the car is not running

 

[stevesey]

Exactly, so when the sensor cools down and works again doesn't the red light show to indicate the stored fault code (do Mercs not do that?)

 

[television]

Exactly, so when the sensor cools down and works again doesn't the red light show to indicate the stored fault code (do Mercs not do that?)

Only sometimes in the case of this sensor, it may not be able to record the fault due to the engine stopping

 

[stevesey]

Exactly, so when the sensor cools down and works again doesn't the red light show to indicate the stored fault code (do Mercs not do that?)

Just got the car back and tried to check that the red light is working. Couldn't find one - checked handbook and there isn't one So there's nothing to warn me of stored (intermitent) fault codes - until the car finally dies that is (or goes into an obvious limp mode).

Time to research 38 pin to DB9 connectors and PC based OBD fault code readers

 

[arorat]

Had a Crankshaft Sensor Failureon a 98 C240 with 100K today (sound faimiliar).


There is a question at the end of this though - I didn't get any red light indicating that there was a fault code I might want to look at. So:

a) Should I get a red light for an intermittent Crankshaft Sensor failure? Or the the light only displayed when the fault is present - which is a bit silly as the engine dies so all the lights come on when you try to restart.

b) Do MB ECUs rely purely on the crankshaft sensor - so dead sensor = dead car. VXs (still Bosch) use the camshaft sensor as a backup - so unless both go engine will still run quite well.

c) Should I get a red light for any intermittent failure - or am I supposed to guess when to plug a fault reader in?

Cheers

Steve

When my car died whilst driving, the the engine light came on, but no indication prior to that. Hope its sorted now !!

 

[kaz786_2000]

help needed.
i have a c240 converted to LPG. it has a starting problem. becouse the car been put onto lpg the top cover has been rised up. the airflow mass meter at the back of the engine dosen't fit in its place. The car is taking in too much air. when it starts it cuts off. but when you start it on lpg its ok.
the lpg working fine but when on petrol becouse of the air flow cover places higher and not sitting on the air flow mass meter. can you help.
should i make a plastic tude to fit on the air flow mass meter and fir into the ait cover or IS THERE ANOTHER PROBLEM.

this car is a 2001 plate v6 motor. its been service and new fuel pump fitted.

Help needed