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Citroen C3 2004 1.4 8v TU3JP - suspect misfire

Posted: Sat Jun 24, 2017 6:17 pm
by Steve
Hello, can you help with the following waveform captured using your ps settings file?

The vehicle is a 2004 Citroen C3 TU 1400 cc 8 valve engine with intermittent misfires attributed to cylinders 1 and 2
Secondary ignition and injection opertaion are correct
Fuel pressure and fuel quality are good
Valve timing inspection confirms no error, I suspect possible compression issues from sticking valves

Could you analyse the attached waveforms from cylinders 1 and 2?

Re: Citroen C3 2004 1.4 8v TU3JP - suspect misfire

Posted: Sun Jun 25, 2017 8:52 pm
by admin
Hello,
Converted files is attached
CYLINDER 2 P0302.p.mwf
(11.69 MiB) Downloaded 206 times
CYLINDER 1 P0301.p.mwf
(15.8 MiB) Downloaded 220 times
To run automatic analysis, in the USB Oscilloscope software select menu Analysis => Execute script

1. Your pressure sensor is inaccurate, so received pressure graphs are distorted and the Px script report may not be accurate.
2. When you recorded the signals from the 1st cylinder, you snap the throttle incorrectly - you pressed the accelerator pedal too smoothly. Therefore, here the Px script report is incomplete.
Signals recording from the 2nd cylinder is OK.

PS:
The CSS script is used to determine the causes of the misfires.
You can record signals for the script using the settings file -
CSS.pssettings
(3.99 KiB) Downloaded 233 times

Re: Citroen C3 2004 1.4 8v TU3JP - suspect misfire

Posted: Wed Jun 28, 2017 2:59 pm
by Steve
Thank you for the feedback.

I will study the results using the PDF file as I am fascinated by the contents in the report for cylinder 2.

The vehicle is now off site but I will try to obtain the crank signal data as soon as possible.

Once again, thank you

Re: Citroen C3 2004 1.4 8v TU3JP - suspect misfire

Posted: Mon Jul 10, 2017 9:00 pm
by Steve
Hello again, sorry for the delay

Here is the crank signal as per the script video
Citroen_C3_2004_Petrol_20170710-0001.psdata
Crank signal with ignition sync
(16.72 MiB) Downloaded 227 times
Regards, Steve

Re: Citroen C3 2004 1.4 8v TU3JP - suspect misfire

Posted: Tue Jul 11, 2017 2:38 pm
by admin
Hello,
Converted files is attached
Citroen_C3_2004_Petrol_20170711-0001.p.mwf
(7.83 MiB) Downloaded 209 times
On your record, misfires at idle speed are not detected, since the engine was running idle for a short period of time. Please record the signals again, and allow the engine to idle for a longer (up to 1 minute) to manifest the malfunction and capture it on the recording.

PS:
Your ignition spark sensor is very inaccurate.