Missfire issue
 

The interesting part is that it is all on the same engine.bank. I would leave the timing chain for the very end. Do check your primary cat. i don't recall every hearing of the timing chain issues. i now have over 150K miles on my engine and i used to race this car at the drag strip and no timing chain issues. 2002s are known for the cam issues but like i said, check the primary cat first.

clogg cat causes misfire since exhaust cannot escape and cylinder mixture is not correct so does not burn good and produces less power.

QUESTION.
See intak seals on driver side (RH in picture) should they not be flipped over?
Seems I see where they are not sealing completely which wouldcause a misfire on driver side.

My god what SQUIRREL was in your enginee bay eating nuts?
IS that shells down below?

My thought exactly! DUDE - get rid of the squirrel/rodent or nothing is going to matter. It will chew up your main harness and then the vehicle is toast. At that point, I hope you have full coverage.

Have you checked the cats yet? I had the same symptoms on my slk32.

I data-logged everything trying to sort this and noticed my boost would go up as high as 26 psi at the point of failure (normally 20 psi with a 62mm sc pulley).

I tapped the cats and noticed only a small rattle on the passenger primary. I dropped the exhaust and discovered that the passenger primary cat had broken in that the first 3rd of the catalyst element had broke away and rotated inside the can causing unacceptably high back pressure under medium to full throttle. I busted out ALL of the cat element and put it back together ... ALL is fine now.

I am assuming that the elevated back pressure raises the cylinder pressure to the point where the plugs can't fire (even with the .032" gap I was running).

hope that helps,
Chris

hi Chris sorry late reply been working and been sent loads of incorrect part by my supplier.

so I took advice from you guys rebuilt the car. Been stood for a year because I thought it was the timing chain. Thermostat was ****ed but couldn’t get old if one. repaired two snap bolts that hold the water pump. These parts Dealer only in the uk.
so I removed the centre of the thermostate . The breather that goes to the throttle body was mashed so tidy that up. Started the car ran on all 6 cylinders. Just gave her the 3rd road test of the day after bleeding the system. Pulls like a train and slides easy with the two way diff. Now I haven’t touched the cats at all yet.
how are you measuring boost pressure. I got a Bosch system for error faults and actual valves
Cant see how the breather pipe or the thermostate would cause the misfire.

thanks again guys for your help and support

put a right smile on my face tonight

I measure boost 2 ways on my SLK32. I have a dashdaq that plugs into the obd2 port and reads the value that the ecu perceives from the MAP sensor. I also have a ZT2 (Zeitronix wideband data logger) that reads a pressure sensor that i have screwed into one of my intake plenums. (on my sl55, I measure it 2 ways as well, with an "aeroforce interceptor" gauge plugged into my obd2 port and a "techedge" wideband data logger that reads a pressure sensor that i have screwed into one of my intake plenums).

You don't need to have all that hardware, however ... were I you, I would find a scan tool that plugs into to the obd2 port (there are many solutions for under $100, some are handhelds, some have a display that you mount on your dash) OR, get an ELM 327 wireless dongle
and plug it into your obd2 port and read it with "torque" (smart phone app).

hope that helps,
Chris

thansk for your reply Chris. I’ve got a very good scan tool which is the same as local garages use Bosch system (works computer) I’m sure I couldn’t see a actual value saying boost pressure il have another look today at the list of values.
thansk again

a good scan tool that has "live data" should be able to read/display "MAP" (manifold absolute pressure) ... this is often expressed in inches HG or BAR and you have to translate. you could get something like this ultragauge https://ultra-gauge.com/ultragauge/u...RoCVkQQAvD_BwE

but if you have an android smartphone, I would recommend the elm327 and the torque app that I mentioned previously.

cheers,
Chris

U know cylinders 123 are passenger side right side 456 is left side driverside
they are casted right on ur valve covers

Help
 

Hi guys thanks for your help sorry delay in a reply. Car been at the bodyshop for a touch up. Got it back left the car running to charge the battery. Now got a coolant warning fault

Right had to set up a new account so I can post on here. Hi everyone hope you can help.

charging the battery on my car today. Came up saying check coolant.
Gauge showing a temp of 85c
checked coolant and it was fine.
Plugged in my Bosch scanner. Connected to the air on ecu.
coolant temp 103 and rising.
no coolant fan kicking in.
Turned the air on on to see if the fan works.
And checked actual values. Triggered in at 20 percent. But shortly goes off.

so did a actuator test on the radiator fan.
Does not work while doing the test.
so I unplugged the coolant temp sensor. No fan working and bridged it still nothing.
i checked for supply. I unplugged the fan control unit. Two main feeds one with a 12 supply. Also swapped the feeds and had a earth on the other main supply.
Two smaller wires. Same one with a 12v feed.

can anyone help before I start buying fan units because seem to be hard to find. Also big bucks.

Cheers in advance