Technical Surging- Fiat 500 Pop 2012

[Hansgiant]

Hello,
My 500 seems to surge. It happened at slow speeds or when you are trying to drive slowly.
Also at higher speed when you take you foot off the gas to decelerate.
It has just been in the shop for a timing belt/water pump change as well as a full service.
Also seems to be down on power.
I was thinking perhaps coil pack?
Any advice would be most welcome.

Best

Hans Giant

 

[jrkitching]

It has just been in the shop for a timing belt/water pump change

I think that's the key sentence here.

If it was working fine before the belt change, it's unlikely to be something unrelated like the coils.

We've seen seemingly endless posts here from folks expressing running issues after a timing belt change. It's easy to go wrong if the correct procedure isn't followed. Garages without specific Fiat experience who just treat it like any other belt change are some of the worst offenders.

Almost certainly the engine is now mistimed.

 

[GettinBetter]

As above, and perfectly put.

 

[John202020]

Try driving it quickly say 70+ or slower in a low gear for several minutes if the eml comes on and the car goes into limp mode its the timing, off and restart will get you home just don't rev it too much?