FIAT 500 - Px sincronismo incorreto

[Diogo_Vieira]

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 (142.42 KiB) Viewed 24149 times

[Ygryk]

fiat 500 CSS 4 channel00.mwf

No misfires

Efficiency.png (45.26 KiB) Viewed 24146 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:

 
 
 
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.

VVT system works

Phase CMP.png (141.9 KiB) Viewed 24146 times

[Ygryk]

The timing has been checked with appropriate tools and is in order. The valves were correctly calibrated.
 
Px35+Flex00CIL1_fiat500.mwf
 

The "Valve timing" tab of the Px script showed the following real values of the valve opening and closing angles:

Inlet open: 349° after TDC = 11° before TDC

Inlet open.png (69.64 KiB) Viewed 24146 times

Inlet close: 582° after TDC = 42° after BDC

Inlet close.png (65.97 KiB) Viewed 24146 times

Exhaust open: 113° after TDC = 67° before BDC

Exhaust open.png (71.29 KiB) Viewed 24146 times

Exhaust close: 355° after TDC = 5° before TDC = -5° after TDC

Exhaust close.png (68.84 KiB) Viewed 24146 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]

Px35+Flex00CIL1_fiat500.mwf

The Px script showed that during a sharp throttle, the engine sucked a little amount of air-fuel mixture.
 

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Intake system.png (38.99 KiB) Viewed 24140 times

Intake diagram.png (22.34 KiB) Viewed 24140 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.