W210 engine suddenly stopping!

[MarkwithaMerc2]

I would be tempted to go for a long Italian tune up then start with the diagnostics afresh.

What? I have heard of all sorts of things Italians can do but never a long tune-up!! Interesting stuff to think about though!!!

 

[MarkwithaMerc2]

EGRs are everywhere.

I don't think its one of those problems where an EGR/exhaust/TPS is clogged up enough to cause rough idle/ stall. If it were, it would happen with much more vigour.

The initial description you gave was the car works fine when cold and then stalls etc after a few minutes. To me that means it warms up first and then, when its not operating on cold engine settings anymore, it starts misbehaving. Plugs & leads can do this. MAF is known all over the place to do this. Exhaust/EGR... probably the least likely to do this. Electrical flow/ charging - I think we've ruled that out although that would explain the ABS-related warning lights.

The MAF can be cleaned as well. In fact, another couple of screws and you can get to its insert and really take a closer look. Check out:

http://www.benzworld.org/forums/w210-e-class/1328069-maf-diy-pictorial-replacing-cleaning.html

I want to do this too - but I'm a few thousand miles from my car at present so I'll just have to wait.

PS Best not to call me Malcolm - if you upset the TV he'll cast a spell on all your future MBs and there aren't any pneumatics in pumpkins.

Haha! My profuse apologies to Mr TV/Malcolm! I don't wish any more bad spells to be cast unless he can turn my pumpkin into a coach at midnight! (Hmm, mixed metaphores! Apo-loogies again!)
I am checking-out the Benzworld site now...

I was discussing MAF's with a very knowledgeable electrical guru at work today. (He drives a de-catted Lotus Carlton as his everyday transport! Why?Don't ask!!! He says its got 3 litres and more than six cylinders! That's his minimum spec. for a car).
He seems to think that it, (the MAF not his Lotus), is a very simple instrument and, given a suitable resistance to connect across the plug terminals, should prove either way if it is operational or not. Problems arise when I look for correct voltages applied to the wire element, expected currents and exactly what signal the ECU is expecting. I am sure this has been looked into in depth elsewhere so I will stop there until I look closer.

MAF looks very clean but I guess wire corrosion may play a part in its' degradation. But then so may the connections?
I will assmble the throttle body on this fine, up-coming weekend and, anyway, book it for an MOT. Lets se if the emissions test shows anything...

An aside: Where are you in the world? A few thousand miles away could be South America or the glorious Far East! I am curious!!

Thanks again Gents!

 

[Frontstep]

Its just an expression for a high revving run.

 

[BachelorDays]

The thing is to get it idling good (or goodish) and then ensure it runs smooth when fully warm as well. I wouldn't play with the MAF off soon before an MOT. Even if it looks clean, Halfords et al do MAF cleaner sprays (a fiver or so). You could give that a go. Can you date the MAF (ie any record of it having been replaced)? Is it original MB?

You are right about the MAF. Simplest imaginable setup. Just like the Crank position sensor. However, for some reason, these two don't always align themselves to simple diagnostics. But then, MB seems to be full of such gems. A fan goes and the whole car shuts down. A light switch blows and it can throw the car in limp mode. An air flow sensor has a spider crawl across it and a moving car loses its throttle.

I used to have a w126 (500SE). That thing decided one fine day it won't start. 7 days later with conferences between Germany and here and they finally figured out they had to 'reset a computer' (as terminology went in those days). Just because I'd pushed it past 100 in 2nd. That was my first encounter with electronic controlled cars getting over-enthusiastic. 10 odd years later and, instead of getting the software to be intelligent, someone decided its a great idea to put in a system shutdown in a moving car for every eventuality. Bravo!

I'm presently in a country where all hell is about to break loose. Just East of Middle East. I hope Singapore agrees with you. They have a nice art gallery they are very proud of. Driving, I have heard, is enterprising.

 

[television]

Early MAFs were just a quite simple hot wire, and the air passing over the hot wire was measured by the resistance of any cooling affect, and this changed the fueling.

Modern MAFs are very different, in most case on petrol engines the will not get dirty unless an oil problem like on many where the CAM sensor leaked oil into the loom. But with all MAFs both old and new the air flow speed is colossal and this air will contain micro grit that the filter was unable to hold back, this in turn slowly erodes the wire in the early ones and the elements in the newer to the point that they go out of spec and can no longer control the mixture correction.

Oil is not resistive at at all as the good oils separate the molecules so not much gained in trying to clean them. Once they go out of spec its quite rapid and almost to the point that fine one day and no good the next. turning off the engine and then back on again will sometimes prove the point as the heating part gets a chance to start up again.

Here is a modern one that I have cut away so you can see the elements and micro chips within.

 

[BachelorDays]

Thorough as usual, Mr T! I had no idea they had changed that much. I wonder if a new MAF for my W210 will now have this element setup?

 

[MarkwithaMerc2]

Hello again Gents!
Many many thanks for these very interesting posts. I have had a bit of a week so far and only just this last few minutes got the throttle body back together. Started it up and except for the CEL which has returned, the engine starts and runs on cold and warm idle just like it should. I disconnected the MAF and tried again and this time the 1200 idle was fine but the engine didn't stop!! It dropped down to 900 revs and ran rough again, just like it did before I started playing with the throttle body.
I think the MAF is therefore OK and I THINK it might just be a bad connection on the MAF plug or maybe degradation in the loom. Anyway, not had a chance yet to take it for a run yet but will do so tomorrow before son-ly duties take over with nonagenarian parents...! Definitely not as much fun as playing with Mercedes!
I will check the CEL on the OBD and see what that says too.

I have checked the pretty comprehensive history and can find no MAF renewal. So I guess its original. Can't find anything written on it except PBT GF 30. But I didn't check the make when I had it off the car. Maybe there is something written underneath.

We will have to get there soon as time is moving-on now and I need the barge sooner rather than later!
Thanks again Gents!

 

[MarkwithaMerc2]

What can I say, SUCCESS!

:lol:Hello again Gents and this time it is with a BIG SMILE! But it is a qualified BIG SMILE as although the car is MOT'd now and running like clockwork, I still have no real idea what caused the original problem.

I re-fitted the cleaned, very dirty, throttle body a week or so ago but although I started it afterwards I didn't have a chance to drive it.
Today I phoned the MOT guy and booked it in again. I started it up, checked the codes and is still was showing multiple miss-fires on nearly all cylinders. Took the beast for its usual 'walkies' around the block, CEL was on and it wouldn't pull, fa*ting around and generally sounded unwell. But it was running and idling OK even roughly. I called the MOT guy and he suggested I bring it in anyway. I went to the garage to get some fuel, stuck £25 in and started it up to drive away. MAGIC! The CEL light as well as the petrol light went out and the 'ol girl was RIGHT back to normal again! (It can't have been petrol starvation could it? Maybe I don't want to know the answer actually!!)

Cheating the DVLA for a while, I took it around the area for a couple of miles to try to get the stone-cold Cats warmed up again and the kick-down was smooth and tick-over perfect!
I took it for the MOT even expecting the cost of a couple of new tyres and emissions failure but everything passed of, nearly, absolutely brilliant performance!
However, mention was made earlier in this thread of dodgy lights and, yes, the off-side headlight was incorrectly fitted, (Not me surely!:Oops, and not working. Fixed by the MOT guy for £2.
The rear fog light had dodgey contacts and, again, fixed by the MOT guy, FOC.

Took the monster home, checked the code faults and although the CEL was off, I couldn't get the apparent codes deleted but I think this is more due to my excitement than correct operation of the laptop!

I don't know what is going to happen to him now but it has some serious work to do before he goes, hopefully, to a good home!

Now all I have to do is find my lost passport! Every cloud has a silver lining with Mercedes and you, incredible useful Members of what MUST be the most helpful Owners Forum on the block are the most useful tool in any Mercedes owners tool kit!
Long may the MBO Forum live and I hope you are still around when I eventually return to UK! Good luck and safe driving!!:lol:

 

[anyweb]

(It can't have been petrol starvation could it? Maybe I don't want to know the answer actually!!)

heh, maybe it was ! either way i enjoyed the read and seeing what diagnosis you did, well done and good luck in Singapore

 

[BachelorDays]

Bon voyage !

 

[Rockall]

It is quite possible that the problem was old petrol - modern petrol contains a percentage of ethanol and left siting in the tank it tends to separate out. This may be the cause of your problem as once you introduced some fresh petrol your problem seems to have disappeared.

Regards

Bill

 

[MarkwithaMerc2]

It is quite possible that the problem was old petrol - modern petrol contains a percentage of ethanol and left siting in the tank it tends to separate out. This may be the cause of your problem as once you introduced some fresh petrol your problem seems to have disappeared.

Regards

Bill

Yes, maybe there should be some re-activation data given on the SORN!

Cheers and bye to all!

 

[television]

Good luck

 

[MarkwithaMerc2]

The guy rebuilding my Jaguar has accepted the baby in exchange for some useful hours welding and grinding! I sold the Audi today without a flinch; getting rid of the Mercedes was so much harder....!
I will have another W210 when I return!


Bye guys!

 

[MarkwithaMerc2]

I thought a complete follow-up is necessary! MAF! Changed it in Euro Car Parts car park and the 'ol girl is now singing sweetly again.
I have lots more problems; Interior light not extinguishing and drivers side pax window wire is in a birds nest! Bye bye C5 UFO!