1997 SLK 230k auto. Missfire after 1800rpm

[flango]

Thanks for your reply Flango. Thats the first guy I had out. He couldnt figure it out but when he left after about 2 hours it was running but the day after it was back to normal & I didnt get chance to drive it anywhere. Thats what it does, it lets you think is ok but turn your back on it & it sticks two fingers up at you!

Sorry to hear that Lee is a top guy, the only others I know who are competent are PE German Marques in Grimethorpe (yes I know) deutche teknik in Donny or German marques Attercliffe. Or you could try the garage I have my CLK booked in for service ETS auto centre Rotherham , see my other thread

Only just seen this time where you are I'm only a couple of miles from you

Hope you get it sorted

 

[slippy]

Its really doing my head in now.
I think I`ll send the injectors away for re furb next.
Ive looked for Deutsche Mark in Doncaster but cant find the unit, wondering if they have closed? Ive emailed Star Car & Commercials in Moorends, may have to try them if theres no change with fresh injectors?


Yeah, youre not a million miles away are you?
Thanks again for your help, very much appriciated.
Stu

 

[John Jones Jr]

I know mine is the same feels like the engine is going to shake it self to bits when it happens....I had to drive it 4 miles home the other day, utter mission when you can't stop to re start..if that makes sense...I found getting it rolling then just feather the pedal to get momentum helps, but like you say when it is first started it's silky smooth ..on mine though the BAS/ASR light can come on sometimes then the engine shake starts...even if it is sat on the drive and not moved any were so I am stabbing in the dark that it may be something to do with the ASR side of things....again just guessing for now......bring back cables and bloody levers I say!!

Faulty Throttle body?

 

[motophill]

hi slippy did you ever solve this problem has i have had mine 6 months with exactly the same problem i am well ****** off with it

 

[slippy]

Hiya mate, Im sorry to inform you that the problem still exists on my car too.

I have not been able to get it to a proper Merc specialist but I think people are looking at it from the wrong angle. Its difficult to explain but here goes......

They are getting the car to missfire, then trying to find out why its missfiring.
The ecu is deliberately causing the missfire by shutting down cylinders 2&3 to protect the catalytic converter from damage.
We need to find out what the initial trigger is, that causes the ecu to to shut the cylinders down.
On my car it starts first time everytime, it ticks over & revs weather hot or cold upto around 1800 rpm. If you rev it to the limiter, its fine. You can drop the rpm all the way down to approx 2200 rpm & its fine.
What does the engine do between 1800 / 2200 rpm??? Something changes in this rpm band to cause the blip...but what, I dunno.

 

[Bert_W164]

If not electrical, do a compression test, that'll at least tell you whether the engine is in good nick mechanically.

That way you know it's electrical so possibly a loom/sensor issue.

The guy I went to didnt have STAR, I only have his word that a friend of his at another garage has used STAR on it so I dont know for definate unfortunately.

Did they give you a report? If not I'd ask for one. Star generates a report of what's going on, it may be worth having a look there.

If no codes, all electrical components are fine, I'd look at mechanical issues, and do a compression test as its cheap and easy and pretty much rules out mechanical issues so at which point you can look at fuelling/other electrical issues.

 

[motophill]

hi Slippy im loosing sleep over it this week , ive read every thing you have written and read all replys taken it all on board and going to the shed for the sledge hammer lol took mine to a merc tuner in hampshire he put it on star and scratched his head lol im an electrical mechanical engineer by trade so im going to look into mine ....will let you know what i do and what happens

 

[slippy]

The last garage to have it says they have STAR but Ive not seen any report. The codes given were the same as the codes I found & the same as the mobile auto electrician found. They did a compression test, again they didnt give me any figures but said that compression was good. The last garage said it can only be an ECU fault but I removed it and sent it for testing. ECU testing in Derbyshire said its fine, no issues.

Good luck with it motophill, hope you get somewhere mate!!

 

[hacksawcats]

Question

Did anyone find a soloution to this problem?