Hello guys,
whenever I start my doblo (especially on "coldish" mornings), it runs rough and it sometimes t dies.

It's a CNG version, so, after 3 or 4 second it switches on gas and it runs perfectly smootly. If I switch back to petrol, it become rough again (I suppose till the engine is a bit hotter).

So, I've ordered spark plugs and air filter, but I'm pretty sure that changing plugs and filter won't resolve my problem: if it runs smooth on cng, it means that the problem is somewhere in the injection or in the petrol delivery system (pumps, valves, etc.).

So, after plug and filter change, I'll go for a chemical cleaning of injectors and fuel system. Do you know some effective cleaner to mix in the tank that you know for sure it works (I mean: you have had a rough idling, and after one or more treatment you solve the problem?)

Problem solved:


https://www.fiatforum.com/tech-talk...etrol-cars-avoid-special-fuels.html?p=4465861