I have two 156's both 1.9 JTD 16V.
A 53 plated saloon 140 hp and a sportwagon 55 plated 150 hp.
Both are maintained by me and all service intervals met etc
The 140 has always sounded sweet and goes well. It has now covered about 140,000 miles .
The 150 was purchased at about 44,000 miles and has now clocked about 60,000 miles. It has always sounded slightly more 'off beat' compared to the 140, its definitely louder at idle and sometimes sounds as though it is missing when started from cold. It seems to go well and does feel quicker than the 150 but the fuel consumption is lower.
I use FIAT ECUSCAN but cannot claim to fully understand all its functions. I think the 150 has 1 or more 'faulty' injectors so I logged the injectors correction signal (whatever that is?) at start up, idle and moderate driving, the graphs are attached below in that order.
Does anyone have any comments or suggestions?