Help needed! C180 Kompressor 55reg W203 auto

[Dave wood]

Ok just been out and started her up from cold!. Starts no problem! Idles at 800 no issues. Press the acceleration goes to 4000 but is clear there is a slight misfire.

 

[Dave wood]

No MAF was clean! No oil!

 

[Arudge]

No MAF was clean! No oil!

Good. Oil in the induction system is a known issue and will destroy a maf.

 

[Arudge]

Ok just been out and started her up from cold!. Starts no problem! Idles at 800 no issues. Press the acceleration goes to 4000 but is clear there is a slight misfire.

800 is too high. Is it still 800 when warm?

 

[Dave wood]

Ok I seem to have more than 1 post. So my apologies to all!

 

[LostKiwi]

Ok... So when cold the car runs open loop from the ECU map with no correction from Lambda. As it warms up it will switch to closed loop where it feeds back information from the lambda sensor to correct the mixture.
So... The lambda could be bad giving spurious values to the ECU.
There could be an air leak as Andy suggests which is screwing the mixtures when warm but not cold (when mixtures are already set rich).
I think I'd be getting the codes read properly on an MB reader but as a first step listen carefully for any vacuum leaks.

 

[Dave wood]

Yes I went out had her running for 5 min and it seems to be sitting at 800! Dose this mean it's a vacuum issue?

 

[Arudge]

Right now I'm thinking air leak possibly through the vacuum pump or the brake assist vacuum line.

 

[Arudge]

Do you know where the vacuum pipe is that goes into the brake service?

 

[Dave wood]

Ah ok so could be vaccum leak! Ok right I'm gonna go down now and have a listen to see if I can hear anything!

 

[Arudge]

Sorry. Brake servo.

 

[Arudge]

You may not hear anything if it's leaking through the vacuum pump.

 

[Dave wood]

Vaccum pipe to break service, yep I know

Do you know where the vacuum pipe is that goes into the brake service?

Yep I know, what u got in mind Arudge?

 

[Arudge]

The brake servo vacuum pipe test.

Bear with me.

 

[Arudge]

Start the car.

Pull the vacuum pipe out of the servo and put your thumb over the end of the pipe to seal it.

Your should feel the vacuum acting on your thumb.

Is it 1. You can feel the pipe sucking on your thumb.

2. Sucking quite strong.

3. Sucking so strong it feels like it's going to suck your arm in.

 

[Arudge]

I'll be back on a bit. I really need a shower.

 

[Dave wood]

Right went out started her up and let her worm up. Idle is sitting at 750 (worm) pulled pipe off of vaccum covered servo with thumb suction is strong!

 

[Arudge]

It should be rediculasy strong.

Obviously, your idea of strong could be completely different to my idea of strong.

What I'm thinking is this. 750-800 rpm at idle is too high. The car may start off the key and the idle be stable, but it's too high. I think the vacuum pump has failed and your leaking air because of the failure, I've had this on my w208. The vacuum pump impeller fails and bits of it get stuck in a one way valve allowing air to leak in, leaning the mixture right off creating the miss fire.

The image is the pump your looking for, it should be under the inlet manifold.

I have written a thread, I'll just look it up and post the link.

Others have made some excellent suggestions and they should all be explored.

 

[Arudge]

Have a read.

http://forums.mercedesclub.org.uk/index.php?threads/clk-200-kompressor-w208-vacuum-leak.162619/

 

[Dave wood]

It should be rediculasy strong.

Obviously, your idea of strong could be completely different to my idea of strong.

What I'm thinking is this. 750-800 rpm at idle is too high. The car may start off the key and the idle be stable, but it's too high. I think the vacuum pump has failed and your leaking air because of the failure, I've had this on my w208. The vacuum pump impeller fails and bits of it get stuck in a one way valve allowing air to leak in, leaning the mixture right off creating the miss fire.

The image is the pump your looking for, it should be under the inlet manifold.

I have written a thread, I'll just look it up and post the link.

Others have made some excellent suggestions and they should all be explored.

That not what I had my thumb on! Lol. The pump I had my thumb on is at the back of the engine!

Yeah I get what u mean. The suction was strong it held my thumb good!
I've attached a pic of the pump I had my thumb on! (This is off of 2007 C180 ) I had to take this off of the engine and put on mine off of my old engine a 2005 (55) c180 as the diameter of the pipe was too big for my vaccum pipe!

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