Please help W202 c200 auto engine revs all wierd

[digre]

Hi all

I’m hoping one of you may be able to point me in the right direction with and engine problem I’m having.

I have a 1999 W202 Auto C200

If I floor the accelerator I can make the engine play up. It will start fine, run fine, but if I floor it, I can make it go crazy…the engine wont rev fully, and gets kind of stuck, as if it is running on only 3 cylinders. At idle it then jumps rather violently. If I then turn the engine off, remove the key then restart the problem goes away, until I floor it again.
On the motor way if I floor the gas pedal it doesn’t rev cleanly through the rev range. One moment it doesn’t have full power then it does, if anything more than normal, then it doesn’t
Any ideas…. It’s obviously electrical, but where???


Thanks in advance…….

 

[Ian B Walker]

It could be a coil pack extension if your engine has them or it may be maf/mas related. Or even a vacuum line.

 

[television]

I think it the MAF cheaper from a Bosch service center

 

[digre]

Just Googled MAF and now know what you mean.
Will give it a go, it can't do any harm, and let you know. Thank you both for the advice.

 

[television]

Just Googled MAF and now know what you mean.
Will give it a go, it can't do any harm, and let you know. Thank you both for the advice.

If you unplug it, that will give you a good indication if it regains full power

 

[digre]

Will take it out tomorrow and make it happen, but instead of restarting engine will unplug MAF. Thanks Television

 

[digre]

Thank you for the advice chaps but I'm affraid it didn't work.
Cleaned the MAF sensor, as you said, but can still make the engine go wierd if I floor the excelerator.

Any other ideas??????

 

[television]

We can discount the O2 sensor, as the lamp is not on,, the EGR only comes in at cruising, ignore fuel as it would recover when you backed off, So as Ian said coil pack as they can break down under load.

Or get the codes read out

 

[digre]

So as Ian said coil pack as they can break down under load. (Easy it fit? Will I be able to fit it? Cost?)

Or get the codes read out

Codes???? Do you mean connect to electronic diagnostic at a garage????

Television I do appreciate your help

 

[television]

Codes???? Do you mean connect to electronic diagnostic at a garage????

Television I do appreciate your help

Yes fault codes, some indies will do it quite cheap,,You do not have to pay MB prices,, we have an indie section, or you could put up what side of London you are

 

[digre]

Mr television I bow to your greater knowledge. MAF it was, had it replaced today at a local independent garage I use that is just down the road from my house. He would only fit a genuine Merc part because he says there is no comeback with non genuine parts????
Any way back to good as new!

How much should I have paid? Part only?

Please tell me it’s loads of money J


Thanks
You are one cool:bannana:

 

[television]

Mr television I bow to your greater knowledge. MAF it was, had it replaced today at a local independent garage I use that is just down the road from my house. He would only fit a genuine Merc part because he says there is no comeback with non genuine parts????
Any way back to good as new!

How much should I have paid? Part only?

Please tell me it’s loads of money J


Thanks
You are one cool:bannana:

Some genuine ones are on Ebay guaranteed to be Bosch, they should be OK,, £100-£140 from Bosch, £275 from MB.


The MAF can go in one of two ways, with diesels they often will clean, but seldom with petrol as the sensor goes out of spec. Pleased you are traveling fast again, don't forget the speed cameras

 

[digre]

Thankyou for your help on this problem. The new MAF did fix everything for a while, but now the engine is again running rough especially when cold. Took it back to the garage 10 days ago and they are running out of ideas. When started from cold it pinks, back fires will only rev out to about 3500 rpm, at idle it is jumping up and down the revs from 500 to 1200.

The guy at the garage is now wanting to take it to a Mercedes garage for a diaognostic check!!!!!

Any ideas????????

I love my old motor and there it not to much wrong with it, appart from this fault, but I don't want to have to throw £100's more, after £300 for the MAF and £275 for it's service this year alone, at a car that is not worth more than £2000.

What a bloody money pit!

Help me please!!!