[Swt70]

Hi.
I have an SLK 170.447 230 compressor. I seriously need help. I been researching my car for 3 months now, the car misfire at 45-5000rpm.
What I have done:
Change sparkplug 2 times different plug.
Chang knock sensor
Fuelfilter, fuelpump
3 diffrent CPS
Change CRP
Try 3 diffrent MAF.
Check injetor
Change coils.
Check vaccum line.
Cleand nozzel inletmanif.
Change O2 sensor.
Check timing on engine.
Sometimes engine start easely (when it is cold)
Sometimes is hard to start, engine can misfire before it start.
Engine runs fine at idle.
Use iCarsoft CR Max as diagnostic tool.
Now faut code.
I'm running out of ideas now🫣.
Thanks everyone for the help😃

 

[BaD_81]

As you already know @Dave2302 will tell you, STAR diagnostic is what you need!
Is a visit to main dealer too expensive for you? I mean, that is not 20€ for spares you mentioned. So dealership diagnostic might be worth after all.

 

[M4rCu5]

Wild guess and I could be wrong but how about the K40 Fuel Pump Relay being at fault?

Costs nothing to remove and examine very closely, like microscope closely

 

[Swt70]

I have swapped K40 with another car, no difference.

 

[BaD_81]

One thing I found easy for me! Work on 1 detail at a time.
Change spark plugs no effect, keep the originals and or the new ones.
MAF swapping the original with supposedly good one, nothing change, swap the original back and keep checking.
Not because of anything else, but a small details in 5 elements are not easy to diagnose.
4500+ RPMS are in need of more fuel and more air, have you searched for vacuum leak?
Do check all the connections you have touched MAF, etc. Then there is a small S shaped hose on that side of the throttle body:

perfect for a smoke machine attach port. Only if you haven't done this.
But you should feel the "vacuum leak" at low rpms too. Higher rpms are fuel cut offs in general. Air filter and Fuel filter being new makes no sense!

 

[Rofa]

Enough may or may not have been said about the need for SDS, but @Dave2302 had made the point often enough.
It does occur to me that you must be using a "38 pin adaptor" with your icarsoft. Is this an adaptor or a multiplexer? If it's an adapter it will presumably only read some basic codes .......if they are there.

 

[Swt70]

I have a 38 pin MB adapter for Icarsoft. Can read quite a bit with it, but don't think it's enough.
I get no error codes. I'll try to put Icarsoft on recording and take a test ride.

 

[Rofa]

Just for fun I thought I'd post this Mercedes Benz Hand Held Tester. As it says at the top of the page, it's for historical purposes only, although there was one for sale last year on eBay. SDS of course simulates the Hand Held Tester. I'm not sure any of the other devices even claim to?

 

[Dave2302]

Classic case of Parts Darts



SDS

Anything else and you may as well call this guy 🤣

SDS of course simulates the Hand Held Tester. I'm not sure any of the other devices even claim to?

A working HHT usually sells for more used than a clone SDS with the C4 SD Connect and FULL lead set

SDS will likely use DAS Program for the ME, but yes SDS DAS switches to HHT when needed for the modules like VR, CCM, PSE, ATA etc

 

[borris1954]

Probably a stupid question but this is occurring whilst driving and not a confusion for the normal rev limiting action if you rev up whilst in park or neutral?

Sent from my SM-T290 using Tapatalk

 

[Swt70]

Hi.
That's when i push pedal to the metal it’s start misfire.

 

[Avel Du]

Hi.
That's when i push pedal to the metal it’s start misfire.

But is the car stationary, or moving?

What Borris is pointing out is that there is a limit on the engine when not moving to protect the engine.

Not for your car but maybe explains what is being said.

Engine not reving over 4000rpm

Hi guys! Just before the winter I've bought the SLK200 kompressor, year 2000. As the winters here are quite severe, I've had the car parked under the roof and every cuople of weeks starting the engine and making sure that the battery is not dead. As the winter is almost over, I started the...

www.slkworld.com

 

[Swt70]

Is when i drive it happens,forgot to write it🙈

 

[BaD_81]

As I was intrigued by the safety feature if the m111, mentioned, I had my engine warmed (back from shopping) and the shifting gear selector was on N, with handbrake enabled. The car was limiting itself aroun 4-4.2 K rpms. I have not stepped on it after and in gear to "test" that limiter. As extra info my old honda had that limiter functioning in the upper red zone, however the accord was manual. So I have my + for the on spot safety feature!
Later today will drive and depending the road conditions may shift to 3 and step on it...

 

[Dave2302]

LOL just slap it in Manual 1st and floor it, let it rev the nuts off it, Engine should go to the Red Line rpm limit and shift up to next gear

 

[BaD_81]

It ain't V8 m8!
It's only 2.3kompressed

 

[Avel Du]

It ain't V8 m8!
It's only 2.3kompressed

V8 in M mode does not have a rev limit. It goes as high as you take it.
Only using manual change in S and C modes have the limit for gear change.

Not sure with the 230, but get moving and down shift on the stick to get a version of manual, that should change at the rev limit.

 

[Dave2302]

R170 doesn't have M Mode, (well mine does, and Agility too) but I digress ...........

R170 Modes wise only has W and S but the Shifter stick on pre facelift cars goes 4, 3, 2, 1 as opposed to Tiptronic on Facelift

Hence I said stick it in 1 (M) for Manual), but that isn't a mode, bad description by me I guess

The 4 Cylinder revs higher than V8 IIRC ?

Anyways, the point still stands, = Stick it in 1 and do a Ttraffic Light grand prix until it revs its K. N. Ackers off

The Rev Limit in the ECU won't allow it to over rev

 

[M4rCu5]

The Rev Limit in the ECU won't allow it to over rev

Dyno Man hates that

The A/T's just change up at certain rpm and there's nothing you can do to hold them in gear 🤷‍♂️
The M/T's have the fuel interrupt at certain revs instead and I've hit that a few times as well 🙃

Bottom Line - out of the box, there is no "thrash it til you trash it" unless we can find this mysterious Dyno Mode

 

[BaD_81]

OK, as Dave pointed my selector is the longest of them all PRND4321, so manual was what I explained limited to 3rd gear as the road conditions, traffic....
Now on the right turn on D, as I am going back home, I see a nice queue of cars (all the way to the right turn, up the road) and a small gap...or in other words pedal to the metal orange Exclamation mark blinking and the RPMS going to 6K and upshifting. It was on Summer mode (sport for some) and after I was away, when lifted my right foot it shifted once more.
So, no limiter was felt (fuel pump braking or anything) and red zone was reached. Some tires and fuel too! As it is a busy time on the road, couldn't exactly go into racing mode, as advised by Dave, because of stupid bicycle ....crossing on the red light after the roundabout. The only possible opportunity for racing mode with no cameras and empty road...next time!