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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?

Diogo_Vieira wrote: ↑

Mon Jun 22, 2020 3:49 pm

fiat 500 CSS 4 channel00.mwf

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.

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
 

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

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.
   
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.

I saw that the exhaust valve timing is a bit off in the Px script. Can this small change affect how the engine works, or is it okay?

Yes, changes in valve timing always affect how much air the engine's cylinders can suck in.
And that affects how much fuel the engine can burn.
And ultimately, all of this will affect how much maximum power and torque the engine can produce at a given RPM.

Ok, Thankyou for this information.

Hello. where can i find that book tiwh the valve specification. thanks for any help.