Why Did This Happen???

[Tan]

"anyway so i decided to trail it without the bass box installed.... 1 hour of driving and car was fine, two hours car was still fine... infact the wholde day ..... the car was behaving normal again... :d..... later on this evening i was sitting in my car sorting out a few cd's still with the bass box disconnected...... the car was running and left it in 'D' with foot on brake jjust to check if it was my imagination.... after about 5 minutes the car stalled on me :'( (the car was just on... no radio was switched on or the bass box)"

Did you have the interior light on when you were sorting out the CD's.... if so could this have been causing the powerdrain??

 

[bhav]

interiour lights were off... my house hass a floodlight witch gives me enough light..... the car is back in the garage today( stealership) they foned me earlier saying they still cant find fault but gonna overlok it againg tomorrow.... so no car at the moment

 

[bhav]

ECU is dead... stealership say £650

 

[sym]

Would definitely try a breakers and see if you can get hold of a second hand one in that case . . . new ECU is a big expense.

Would be interested to know what they believe has caused it to fail. This seems to be a more than occasional fault.

S.

 

[GrahamC230K]

ECU is dead... stealership say £650

Not a bad price for an ECU.

I think mine was about £750ish.

Labour to fit is not long.

 

[bhav]

look at this link.....

http://www.carclinicmagazine.com/Diagnostic_Proceedures/Mercedes/mercedes.html

hang on i paste the main bit... tell me if you think it might be same problem...
(I know my car isnt a 4x4 but suffers from the same problem, where will i find the fuel pump???)


Four Wheel Drive vehicles are very much in vogue still, must say I Can’t understand why anyone should want to be a fashion victim. The particular vehicle in the limelight this week is a bit of a rarity in the off road world, the Mercedes 420 G. Powered by a 6 cylinder fuel injected Mercedes engine & automatic transmission, it was rather better than most of it's kind. I couldn't help but recall the first time that this vehicle came to my attention was when an acquaintance of mine took a brand new one of these vehicles down onto a beach to demonstrate it's ability's to a customer. Unfortunately his ability as a salesman was not equalled by his ability as a mariner and the vehicle submerged along with his job. Anyway this particular vehicle had a fault of the engine cutting out intermittently. The problem here with diagnosis is that when an injected engine cuts out if it is due to ignition loss then the petrol pump is made to cut out automatically a fraction of a second later as well - this is a safety feature to prevent the petrol pump from running in the event of accidents. When the engine is cutting out it is impossible to tell by looking at the petrol pressure and ignition signal together which cuts first since the two appear instantaneous. We found out which by datalogging the signals concerned onto my laptop and then inspecting those signal levels afterwards for the time of the engine cutting out. It turned out to be the fuel pressure that was disappearing first, so the next step was to monitor the electical supply to the pump when the problem occurred. This cleared the pump of suspiscion since the pump was losing it's positive feed then. Tracing the wiring through to the pump revealed some tacky looking insulation, some completely bare and likely to be shorting out, so this was repaired and a relay that had probably sustained damage in consequence from the wiring renewed also. Subsequent testing could not make the fault re-occur, so the vehicle was returned to it's owner for reliable service once more.

 

[guydewdney]

i ahve the same problem - i reckon its a heat related thing - with it in D after a long drive at high speed ( ) then sitting in traffic, it can severly missfire. no fault codes at all.

replaced engine temp sensor - no difference.

Andy gale recons it can be the breather pipe from the right cam cover tot he air intake -- im dubious, but at 14 quid, it gotta be worth a try. the old pipe was fecked - and like plasticene (sp?) squidgy and soft.

as soon as i drive off its fine, just tickover has the problem. Mine has never cut out - but then I have 8 cylinders, in two banks, not 4 or 6 in a single bank....

no help really - but check the breather pipes from the cover to the MAF? ??? 111 018 04 82??? its the 220 petrol one tho'

 

[bhav]

just been out to see the car again... its definatley not loosing power when it misfires... now it isnt even turning off... it just miss fires badly.... the voltage isnt dropping to the fuel pump niether.....the breather pipe seems to be quite firm and not that squidgy.... im begining to thing it must be the ecu....

im gonna go mcp tomorrow to get a quote and see how much they carge to remap it...
i'll let you know what they say..