Merc A class revs up and down at start.!!!

[des3gi]

Hi everyone,
I recently bought a Merc Class A T Reg. I went through the usual checks and everything seemed to be ok. The next day though when i started the engine i noticed that it was reving between 0 -1000 rpm going up and down constantly for about 2 minutes and then was normal. I had a diagnostic check at a local garage and also had the throttle housing cleaned.....still the same problem.

Three messages displayed on the diagnostic device:

P0170: Self adaption low, part load too rich. Idle too rich, adaption too lean.

P0130 :Oxygen sensor, before cat minimum voltage.

P0301 :Misfire cylinder 1.

Could someone advise me what else to do please? Has anyone faced a similar problem in the past?.

Thanks

Greg

 

[Dieselman]

That sounds like either the Lambda sensor is going down or the MAF. The misfire could be faulty plug caps or a faulty injector sticking open so needs checking.
A faulty injector could be causing the over rich mixture.

 

[des3gi]

Thank you for the instant reply. Does it cost a lot to replace parts or fix the problem? I ll follow your advise and take it from there.

 

[partsspecialist]

Hope its the lambda and not the MAF. On the petrol 168 Aclass the MAF is part of the engine ECU and is far from cheap, needs to be ordered to chassis no and needs some coding in the workshop.
Misfire could be the ignition coil, quite common.

 

[des3gi]

What sort of cost are we looking at for the Lambda sensor, what for MAF, and what for ignition coil. How could you tell for sure if the problem lies on the Lambda sensor or on the MAF please?


Thanks

Greg

 

[partsspecialist]

Ok Greg brace yourself, ive priced these from an A140 without your VIN im making an educated guess.

Lambda upstream(before cat) £171.55
Lambda downstream (after cat) £171.55

MAF/ECU £1051.63 comes from Germany only and takes 5 working days.

Coilpack £98.11 is one big coil that covers all 4 sparkplugs.

Prices are retail and include VAT.

 

[grober]

There are alternatives you may wish to explore depending on your finances and the value of your car. http://www.aclassinfo.co.uk/mypage.38.htm

 

[Dieselman]

There are alternatives.

Yeah. Get a diesel...