my car mileage is 128000km.
change all of spark plugs and coils at 127000km


My car shake at idle repeatedly. this symtom is not regulary. but when shaking happens, my room lamp's led light trembles and alternator voltage get dropped... at this time, I push accelator up to 1000 rpm. this shaking symtom is clear and light is no more trembing..also alternator voltage get to 14.7V

Even if I change all of spark plugs and coils, my car sometimes occur misfire on cylinder no.4 when driving over 100km distance.. this problem occured on cylnder no.4 repeatedly.

When I checked CAM magnet and shaft sensor, it looks fine without oliy.

Base on upper symptoms, there is no more error on OBD2. Is there any idea or experience like this problem?

If you have not already done so check fuel injector(s).

What brand of plugs and coils did you install? Have you swapped coils to see if problem stays on cylinder 4?

Was the problem on cylinder 4 before replacing coils and plugs?

Injector test, if you access to Xentry as noted above.

thank you I will check injector first.

I change after market brand from BBT and bosch. I did not swapped.

-misfire problem occured before replacing and current. both are same misfire on cylinder no.4

yes, I will run injector test

FYI

The DI engines require "indexed" plugs... there's been info on non-OE plugs not indexing correctly. The OE plugs are made by Bosch for MB, but a few member have tried Bosch plugs and they don't index correctly. I see FCPEuro has Bosch (OEM) plugs that supposedly are "indexed"... I wonder if anyone has experience with them.

Never heard of BBT.... typically their BERU or Bosch for MB.

thanks for comment. mechanic said BBT is just selling brand that plug is original part from delphi. but, If symtom still goes wrong, I will doubt for plug.

Since you have the OBD2, why dont you log these parameters and we can help see what's going on :

01. Short Term Fuel Trim, both banks
02. Long Term Fuel Trim, both banks
03. Fuel Rail Pressure
04. Manifold Absolute Pressure
05. Both upstream oxygen sensor
06. Both downstream oxygen sensor
07. Boost (psi)/Vacuum (inHG) Pressure
08. RPM

All above while : While in PARK
A - Idling
B - 2,000 RPM 15 seconds
C - 3,000 RPM 15 seconds

Log them in CSV file and post it here.

I have the same engine, so I can help compare those values .

thank you for help. I will make 2000 rpm and 3000rpm cases csv data within 10 hours

but, I already have idling data, please refer attached file it was old recording data in park with idling

Can you do a regular CSV file arrangement like below : Me excel and CSV stupid when it come to having sort its data ... LOL
I think yours originally is TEXT form.


Yours




Make it like below please...



Take ur time, no rush ...

of course not, thank you for quick reaponse. is this file ok?

this is final data you requested

idle
2000rpm during 15sec
3000rpm during 15sec


if you share your car data, I also check for each sensor's values.

very appreciate to you, thank you again

thanks

Thanks. Let me study them yah

Kim,

01. Reduce to logging rate to 1Hz or 1 data per second. Now you are at 8Hz it seems and that made many missing data per Hz recorded.

02. Tomorrow morning, from COLD engine, start the logging and keep logging until your engine hit operating temperature 85C or hotter.
Within the same logging period do the 2,000 and 3,000 RPM hold, minimum 30 seconds, longer will be better.
Anyway our engine at PARK is locked to approx 4,100RPM even at full throttle, do a log for that 4,000 RPM too please, 30 seconds.
All these will need at least 10 minutes of engine running.
Today's data is too short a period.


01 and 02 is to confirm the possibility of your Wide Band 02 Sensor , the upstream one and the downstream one, the narrow 02 sensor..... are good or bad?
It is a high suspect at your mileage. 125,000 KM is already a good service life for those 4 units 02 sensors, BTW.

Please confirm that your car only have 4 oxygen sensors .

Whacky behaviour of sensors.


Did the workshop doing your car ever run test to make sure all oxygen sensors are okey ?

Dont take 02 sensors lightly.
These are the data input for ECM to decide fueling quantity aka injectors and Air Fuel Ratio.
In a misfire condition, do always inspect 02 sensors "credibility" before aiming at other components.
02 sensors live in a very hostile environment and 125,000KM is already a very long journey for them 02 sensors.
Also, they are lower cost than the injector

thanks I will make log data within 30 minutes. ^^

Are you having cold enough engine coolant temperature now ?
<40C should be okey

nope, coolant get hot up to 85C now, attached file is logging data.

Can I wait to cold coolant condition?

Kim,

I am repeating again.

01. Reduce to logging rate to 1Hz or 1 data per second. Now you are at 8Hz it seems and that made many missing data per Hz recorded. Stop logging for now what is not needed.
I need better resolution and longer period to see why the upstream Bank 1 sensor is in conflict with its downstream one. One is a bit Rich and one other a bit Lean. Assuming the data are accurate.

ABOVE : you are overloading your logger system.


The data density of true 1Hz will be good enough if there are no data holes, like below.




Please verify.
Kim Wrote : My car shake at idle repeatedly. this symtom is not regulary.
- Is this from cold start or warm start too ?
- What is current ambient temperature on average where you are now ?


02. Tomorrow morning, from COLD* engine, start the logging and keep logging until your engine hit operating temperature 80C or hotter and then you rev up.
*I want to see if you evap purge is kinda stuck or not.
Within the same logging period do the 2,000 RPM and 3,000 RPM and 4,000 RPM hold, minimum 60 seconds yah. Longer better, less DONT.

Today's data is too short a period and the data holes in your file , made my migrain re-surfaced.


DO NOT LOG THOSE IN RED THIS TEST. We keep you logger light and fast. I want the green ones.


.







I am still messing with ECO charging algo , that is why my RPM at idle is higher than yours.
Tomorrow I will get it back to the same idle RPM as yours and I will also do the SAME test I wanted you to do.
So that we can compare notes apple to apple.
I am at 30-32C ambient temperature .

Later...........

Sorry for logging rate, currently I cannot found to change logging rate yet. I'm using Car scnner app with connecting blutooth ,but I do not know where chaging logging rate yet.

Please verify.
Kim Wrote : My car shake at idle repeatedly. this symtom is not regulary.
- Is this from cold start or warm start too ?
--> yes, shake are occured from cold start and warm start on everytime but irregulary.

- What is current ambient temperature on average where you are nowar
--> I tested my car in basement garage. ambient temperature on 30C.

I will log with some sensors you selected within 12 hours. thanks thanks.

Hi Kim,

After revving up the engine to 4,000, let it idle back for 5 minutes please. Let sensor reading stabilized.
I need to see the 02 sensor past 650 Celcius. Upstream 02 sensor need proper operational temperature. Hopefully after the 4,000 rpm it can hit 650C at least.

Maybe this will help with logging frequency adjustment
https://www.carscanner.info/optimizi...nection-speed/
I am only familiar with Torque App sorry. Torque can only log 8 parameters to CSV file, that I find too little.

Also try :
01. Remove all fuel economy monitor/tracking feature and the like.

02. Remove all TroubleCode tracking.Distance traveled since codes cleared (km)

Distance traveled with MIL on (km)

Distance travelled (km)

Distance travelled (total) (km)

Good luck

ADD :
Becareful please with basement garage. Is the ventilation good enough ? I dont want you to get carbon monixide poisoning.

.

I've not logged either of my E400s, but I have analyzed lots of other cars. Those LTFT numbers do not look right to me.

Our basemment garage is big, thank you for comcerning.

attached file is logging data that you requested. thank you for help me!!

during logging, shake is coming every time.