1st post for new user

[merccopper]

I have an old C180 sport (1997/R) which has covered 131000 miles. There are two flat spots on acceleration. the 1st is around 4000rpm and the 2nd at around 5800rpm. I have replaced the MAF with a brand new Bosch unit but the problem persists. There are no warning lights illuminated on the dash and to be honest i'm a bit stumped as to the cause. Could anyone give me any ideas please.

 

[Alex Argent]

At minimum, you should first disconnect the battery for about half-an-hour to reset the ECU memory.

Failing that, it may be worth getting it into a dealer for a STAR diagnostic check. In any case, it's always best to clear any fault codes present via STAR as sometimes the ECU will not fully reset by battery disconnection. Certainly the fault codes will not be!

Hope that helps,

Alex

 

[television]

You can re set the Motronic ign

Battery off 10 mins
battery on ign on 10 sec
ign off 10 sec
ign on 10 sec crank and start

Welcome to the forum with you popular car

 

[merccopper]

I've completed the above excercises and.......................unfortunately its now running really badly. Into the specialists methinks.

 

[merccopper]

The car now idles roughly and looses power unless i bring the rpm up before pulling away. Any ideas please.

 

[momomo]

When the was the last time the car was serviced?

 

[Spinal]

Sounds like you need a Star diagnostic; if you're friendly with a dealer they should do it free...

Its fairly pointless to randomly "repair" parts when you could know exactly what's wrong with it...

 

[merccopper]

Star diagnostic completed.................new maf, second hand ECU kit (dronsfield mercedes)(mercedes will tell you you cant use a second hand ECU on your car, thats rubbish get a 'kit' from the breakers that includes the ECU, the unit the key goes into and the steering lock) if you need a spare key you must get proof the donor vehicle has been scrapped and then supply Merc with the donor vehicles VIN as the key will be unique to your cars original ECU...........anyway all the new/recon bits on and the car runs much better (thanks to my local specialist Brian at B&R Motors). still not 100% but should clear in a few miles after an 'Italian tune up'......watch this space for further updates

 

[GeorgeA]

... should clear in a few miles after an 'Italian tune up'......watch this space for further updates

Great to get the car fixed there is no better feeling, however curious to know what an italian tune up is!!!

Also, have you replaced the MAF twice!!

 

[jaymanek]

a good ol thraping

 

[sweeper]

Great to get the car fixed there is no better feeling, however curious to know what an italian tune up is!!!

Also, have you replaced the MAF twice!!

once you've driven with an italian you'll understand, lets say they like to keep their engines on the boil, as soon as the revs drop they go down a gear whether they need it or not, just to keep it there.

 

[merccopper]

The car is now much better, but still has a very slight flat spot. Does anyone think replacing the Lambda sensor would be advisable. And does anyone know how much one would be and is it a DIY job.....Thanks

 

[merccopper]

Lambda sensor replaced and the car is like brand new. So if you have a flat spot or the car is running a little lumpy, you could need a new O2 sensor

 

[television]

So pleased its all sorted and we will remember that one

 

[Bobby Dazzler]

Yep great that you updated the post with the solution and results. So few do. Good on you and glads it's fixed.

 

[kth286]

So, you probably spent a lot of money on ECU and MAS etc etc for NOTHING.

Good diagnosis by B&R motors - I think not.