R171-misfire

[elan]

Just bought a 2005 SLK200.Ist journey limped home on reduced power.Next morning car started up no probs,running sweetly,then started misfiring again,engine very lumpy and would not rev.Yellow engine warning light appeared but nothing in malfunction menu.Local garage diagnosed fault as coil on No.2 and changed it.Fault reappeared same day,this time they changed the injector on same pot,still fault did not disappear.
When the fault is on, if the ignition is switched off, the car will restart ok and run till the fault reappears.It would appear something is rebooting when the ignition is switched off and back on again...could this be an ECU problem and has anyone had a similar fault.

thanks...Bill

 

[Miffy]

If a dealer purchase, take it back and demand they fix it at their cost.

Otherwise, stop replacing parts and get your fault codes read out.

 

[elan]

Hi Mark....bought privately,no cumback.diagnostic check showed nothing,this is why they had to start somewhere,so they started with the easy to change bits...thanks

 

[Miffy]

What diagnostic tool did they use? I would have thought any odbII reader would have shown the fault. It must be stored if you went into LIMP. See if you can find someone with STAR to carry out the diag

 

[television]

Could this not be the MAF playing up, worth disconnecting and try the car