Mercedes C180 Engine Management Problems

[strensallmercedesowner]

Hello

I own a 1999 UK C180 (1.8 petrol).

A few months ago, the battery went flat (after I left the keys in:Oops.

Having got it charged up again, I notice that the performance is nowhere near as good. Having done some reading, I realise that the Engine Management System probably reset and needs to learn my car from scratch.

After a month or so of sluggish performance, I reset the system by disconnecting the battery. It did not seem to make that much difference.

Things I notice are that I cannot 'red-line' the car in any gear even 1st or second.

The engine occasionally 'chugs' when idling

The acceleration is nowhere near as good.

Has anyone any ideas or help. Maybe, I have taught the car incorrectly as I have seen various bits of advice of when you reset the ECU, you leave the car idling first. Also, to make sure, I had the battery disconnected for 3 days to reset the ECU but does it need to be as long as that.

Many thanks in advance

 

[Alex Crow]

i suspect you have an airmass sensor fault, if so no amount of disconnected battery action will help. probably worth finding someone to plug it in to make any progress.

 

[strensallmercedesowner]

Many thanks for the reply and I will look into that.

Having looked on Google I notice the following from a post on another forum:

"I have a 99 C180 Sport estate.. I recently disconnected the battery to replace. Since re-connecting the battery i have a problem with the engine revving.. Whilst idle and driving at around 4000 revs the engine splutters and will not go beyond this rev point. If I push the car hard when driving and try and rev past this point, when I stop the car the engine is running in a very lumpy fashion. It feels a bit like it would, if you were driving on an un-round wheel, when stopped. If this explains it....
"

The reply to this was it was an airmass sensor issue and this, give or take the revs (I can get mine up to nearer 5k but it limps), sounds like the problem I have.