W209 clk500 multiple misfire when under load (high rpm)

[aliharry]

Hi all,

I’m having a slightly annoying issue with my car. It has a slight shake from a misfire at idle but not eml however under heavy acceleration (anything about 4k rpm) my engine light flashes on then goes solid, the first time it was just cylinder 3 and I have replicated it since clearing the code to get cylinder 6 and 3 now showing. As well as a multiple misfire detected code. On cylinder 3 I replaced coil pack, spark plugs and ht leads to no avail and I can hear the injectors working using a screwdriver to the ear to the injector method. Before investigating further I thought I’d show you the live data of the car as maybe one of you more experienced weekend warriors could figure out any anomalies that would narrow down my repair route. I’ll upload the pics below any help would be great thanks

 

[BlackC55]

I would do a compression test and a cylinder leak test. Check the timing, check the intake manifold inside and then check the timing. If all that is OK, look at your injectors.

 

[Oleks1992]

Have your injectors tested buddy

 

[aliharry]

Have your injectors tested buddy

New injectors fitted sadly was not the fix

 

[aliharry]

I would do a compression test and a cylinder leak test. Check the timing, check the intake manifold inside and then check the timing. If all that is OK, look at your injectors.

Hi, I replaced the injectors and it hasn’t seemed to solve it, one piece of info I can give is that this entire last week with the extremely cold weather (-5 degrees here )it’s not misfired at all I’m able to go to redline with no issues however today is the first day it was cooler weather 8-9 degrees it’s misfiring again as usual? I feel like that might have some weighting on it as i tested it again and again and in the cold weather it’s been perfect and the first day it’s warmer it’s misfired straight away

 

[BlackC55]

Are your cats blocked?

 

[aliharry]

Are your cats blocked?

I’ve had the secondary cats removed so only primary left and exhaust shop didn’t think they were blocked, but that being said it wasn’t passing emissions on its most recent mot the lambda reading was too high? Could this be an indicator to anything