changed battery/ low power

[Darren-Hull]

Hi, I have a 1998 C180 classic, generally no problems in 5 years, but i had to get a new battery on, which I did myself and since then the engine runs irregular and slow. I'm reluctant to go to far afield to see if the problem resolves itself. Has anyone got any advice or remedies please?
Much appreciated. Darren-Hull

 

[mersum1es]

Was the new battery fully charged? If not, it is charging fully now, and it may cause lower and irregular idle. Or do you mean its irregular even you rev it up?

 

[sjmaxwell]

Is the battery the correct one for the car with the right ampage?

 

[SavMan]

Unplug your MAF sensor to see if things improve, if your adaptation settings have been lost due to no power supply then they will set to the default. If your MAF is ageing or dirty then the ECU will have adapted to compensate if this is lost you can have rough idle and part throttle.

 

[BlackC55]

Very likely to be a faulty maf. As soon as the battery is disconnected the engine control unit re-sets it's adaptation data. If the maf was in poor condition before, the battery disconnection will make it worse.

 

[BlackC55]

Snap!!

 

[SavMan]

Snap!!

I would like to say that great minds think a like but closer to the truth is your great teacher and occasionally I remember parts of it

 

[BlackC55]

I would like to say that great minds think a like but closer to the truth is your great teacher and occasionally I remember parts of it

Thanks. At least I'm good for something!!

 

[Darren-Hull]

Thank you all for the fast replies. So after my night shift I shall

1, check battery, make sure amps etc etc are same/similar
2, disconnect the MAF and see how it runs, if it is no difference then I presume the MAF is ok? (and the fault is elsewhere) if it runs better then i presume the MAF is faulty and a replacement will cure all.

Thanx again folks, much appreciated.