2009 Fiat 500 1.2 cutting out….

[Furyblade_Lee]

My daughters car, and has been running faultlessly for 5 years now. But she is complaining that intermittently the engine simply dies, no warning, but did it last week in the middle lane of the motorway…..
She says 100% if you turn it off and on again it always fires immediately. The dash lights all remain illuminated, no there is no electrical loss, no engine managment light up on the dash, it is as if you turn the key off while driving. My mechanic cannot find the fault, he said there was a code for brake pedal and a code for throttle pedal faults in the OBD but those would not cause this fault?
I am thinking maybe fuel starvation or blocked fuel filter / crud in the petrol tank? Anyone else have any ideas as I imagine this would not throw any codes? Any help appreciated!!! Thanks, Lee

[stevemcs]

Has the obvious been checked, battery cables and earth cables ?

[Furyblade_Lee]

Yes mate.

stevemcs said:

Has the obvious been checked, battery cables and earth cables ?

[stevemcs]

I cannot see it being fuel related otherwise it wouldn't restart, it either has fuel or doesn't, if it was a restriction it would hesitate or stutter under load.

Mercedes and VW's have an issue where the intank fuel pump fails and they just cut out. I think your chasing something electrical rather than mechanical.

[Nigel_O]

Furyblade_Lee said:

My mechanic cannot find the fault, he said there was a code for brake pedal and a code for throttle pedal faults in the OBD but those would not cause this fault?

A failing throttle position sensor could conceivably cause the issue - if the sensor suddenly thinks the throttle is closed it could drop to tick over. However, I don’t think the 500 throttle is ‘fly-by-wire’.

Does the engine actually cut out?

As above - check the simple stuff first - my initial guess will be a frayed or broken earth lead from the engine to the chassis.

[Mound Dawg]

Nigel_O said:

A failing throttle position sensor could conceivably cause the issue - if the sensor suddenly thinks the throttle is closed it could drop to tick over. However, I don’t think the 500 throttle is ‘fly-by-wire’.

The one on my wife's 2010 Punto Evo 1.4 8V is.