Fiesta 1.4 TDCI sporadic misfire

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Fiesta 1.4 TDCI sporadic misfire

Postby victor2k » Thu Mar 15, 2018 8:33 am

On a 2002 Fiesta 1.4 TDCi I have a sporadic misfire al idle.
No fault code related to misfire(P0380 was stored in ECM),the misfire appear at cold and hot engine...
All injectors was tested and found ok,ECM was updated to prevent any software corruption by other service,the glow plugs was replaced ,no improvement on the car.
At the beginning I checked and cleaned the supply and ground points for ECM ,no improvement on the car(sometime the misfire appear after 5 minutes,sometime appear after 30 minutes).
Only when I captured the exhaust pressure waveform the misfire was revealed...
In the attached file you can see camshaft sensor signal(as reference),intake pressure waveform,all injectors current(for a wrong/missing signal from ECM to injectors) and exhaust pressure waveform:
Ford_Fiesta_2002_Diesel_20180315-0001.psdata
only one waveform was attach because of the file size
(5.7 MiB) Downloaded 67 times

Then I made a new capture using only the injector 1 current (as reference ) and the exhaust pressure waveform
Ford_Fiesta_2002_Diesel_20180315-0002.psdata
(6.48 MiB) Downloaded 47 times

With this data captured we have concluded that there is a mechanical engine problem at the cylinder 1.
Removing the cylinder head cover the issue was found:a lost bush of the cylinder head cover at the previous engine repair :D
Attachments
IMG_6992.JPG
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Re: Fiesta 1.4 TDCI sporadic misfire

Postby Mark Dalton » Mon Mar 19, 2018 7:31 am

What is meant to be the function of the bush. Why did the bush cause the fault ??
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Re: Fiesta 1.4 TDCI sporadic misfire

Postby victor2k » Mon Mar 19, 2018 7:50 am

Hello,
Here was the right place of the bush.
I assumed that the bush affected the moment of closing the valves.
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IMG_20180319_074148_HDR.jpg
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