FIAT 500 - Px sincronismo incorreto

Automatic analyzing the cylinder pressure waveform
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Diogo_Vieira
Posts: 7
Joined: Mon Oct 14, 2019 2:21 am

FIAT 500 - Px sincronismo incorreto

Post by Diogo_Vieira » Mon Jun 22, 2020 3:49 pm

Hi. I need help from the experts. The vehicle is a Fiat 500, year 2012. The timing has been checked with appropriate tools and is in order. The valves were correctly calibrated. Can anyone help?
fiat 500 CSS 4 channel00.mwf
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Px35+Flex00CIL1_fiat500.mwf
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infotec500.jpg
infotec500.jpg (142.42 KiB) Viewed 122 times

Ygryk
Posts: 7
Joined: Mon Mar 02, 2015 12:44 pm

Re: FIAT 500 - Px sincronismo incorreto

Post by Ygryk » Wed Jun 24, 2020 9:15 am

Diogo_Vieira wrote:
Mon Jun 22, 2020 3:49 pm
fiat 500 CSS 4 channel00.mwf
Efficiency.png
No misfires
Efficiency.png (45.26 KiB) Viewed 119 times
CSS script "Efficiency" graphs have shown that all cylinders are contributing the same power - there are no misfires.
Dynamic compression in the engine cylinders has not been measured, since at the last measurement stage (after the last sharp throttle) the throttle valve has closed.

To keep the throttle open, you can use Remote Power Off:
Image
 
 
 
The "Phase" tab on channel 3 showed that during a smooth throttle, the camshaft sensor signal shifted to the later side by ~50°. This means that the valve timing control system is working. This system only works if CKP-CMP signals relationship is correct. That is, the Engine Control Unit determines that the timing marks are set normally.
Phase CMP.png
VVT system works
Phase CMP.png (141.9 KiB) Viewed 119 times

Ygryk
Posts: 7
Joined: Mon Mar 02, 2015 12:44 pm

Re: FIAT 500 - Px sincronismo incorreto

Post by Ygryk » Wed Jun 24, 2020 9:18 am

Diogo_Vieira wrote:
Mon Jun 22, 2020 3:49 pm
The timing has been checked with appropriate tools and is in order. The valves were correctly calibrated.
 
Px35+Flex00CIL1_fiat500.mwf
 
Image
The "Valve timing" tab of the Px script showed the following real values of the valve opening and closing angles:
Inlet open.png
Inlet open: 349° after TDC = 11° before TDC
Inlet open.png (69.64 KiB) Viewed 119 times
Inlet close.png
Inlet close: 582° after TDC = 42° after BDC
Inlet close.png (65.97 KiB) Viewed 119 times
Exhaust open.png
Exhaust open: 113° after TDC = 67° before BDC
Exhaust open.png (71.29 KiB) Viewed 119 times
Exhaust close.png
Exhaust close: 355° after TDC = 5° before TDC = -5° after TDC
Exhaust close.png (68.84 KiB) Viewed 119 times
 
The exhaust valve opens earlier than the factory value, and closes later than the factory value. It means that the thermal clearance of this valve is slightly smaller than it should be.

Ygryk
Posts: 7
Joined: Mon Mar 02, 2015 12:44 pm

Re: FIAT 500 - Px sincronismo incorreto

Post by Ygryk » Wed Jun 24, 2020 9:56 am

Diogo_Vieira wrote:
Mon Jun 22, 2020 3:49 pm
Px35+Flex00CIL1_fiat500.mwf
The Px script showed that during a sharp throttle, the engine sucked a little amount of air-fuel mixture.
 
Summary conclusion.png
Summary conclusion.png (13.72 KiB) Viewed 113 times
Intake system.png
Intake system.png (38.99 KiB) Viewed 113 times
Intake diagram.png
Intake diagram.png (22.34 KiB) Viewed 113 times
 
But in this case, it does not mean that the engine is not working properly. It means that the Engine Control Unit has a nuance: when you press the accelerator pedal on a car without moving, it does not open fully the electronic throttle valve.

This nuance can be solved if you use Remote Power Off (I have already mentioned it). After a sharp throttle, the engine must be stopped using Remote Power Off (it will turn off the fuel injection), and keep the accelerator pedal fully pressed to the floor.

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