C200 Sport Auto Estate - Bag of Nails !!

[Greenfella]

I own a C200 Sport Auto Estate Petrol 03/2000 and have recently encountered acceleration and associated problems.

After a few miles, the car becomes juddery (sounds like a bag of nails) when stationery and is very poor at pulling away with little acceleration and the kick-down is poor too.

I can switch the engine off ... re-start it and it is solved for a few more miles.

The AA has been called out and they went through all the normal procedures ... plugs, air filter, vacuum, exhaust and even checked the injectors ... but everything is as it should be.

It was then transported to a local garage and they did all the checks that the AA had done ... even hooking up the car's computer and did a diagnostic check ... fault shows as Piston #2 Injector Mis-Firing. They stripped the car's components down to the #2 injector and put everything back. The fault disappeared. However, within 10 miles of driving away the "bag of nails" problem returned.

Does anyone know what needs to be done ... both the AA and my local Merc garage are at a total loss to know how to rectify the problem. It idles at the correct revs and runs at normal operating temperature.

Any help would be totally appreciated.

 

[Bolide]

bag o nails

With that detailed description I would say it has to be electronic. I'd get a sale-or-return replacement ECU and try that. Or take the ECU to be tested. Or see if the Merc dealer will swop the ECU with one from an employee's car so you can test it out

If the ECU cures it whip out your credit card. If it doesn't I'd look at sensors that would make the ECU make the thing misfire. Does the ECU think it's pinking / overheating / etc?


Nick Froome
www.w124.co.uk

 

[xcombatvetx]

That same problem was happening to me a while back...but i had bad ignition wires, i replaced them and it fixed the problem.

 

[stwat]

One of the ignition coils maybe??

Stu

 

[Greenfella]

Thank you for all your replies - I have printed them out and will take them to the garage ... let's hope it is something straightforward.