Sounds grim. Could the cam belt have skipped a tooth and put all the timing to ****?? Whatever, I wouldn't drive it as unburnt fuel can FUBAR your catalyst very quick, and if the belt has skipped, there's only one thing left to do....
Yep looks like a real Alfa problem ( twin spark engine ) . I don't now the name of it but it has to do something with the timing and cambelt and the injection . It's not really a cambelt shifting but that's something that will happen if you keep driving . You to your dealer to look for this , doesn't cost a lot of money to repair . If you keep driving , very big problems underway ( engine complete waste because the cambelt shifts or breaks and anybody knows wath happens then...).
Hi i have got the same problem and have come on to the site to look for help i've thinking along the lines that it was a Lambda (02 sensor) problem because when it first started doing it there was a rattle from around the cat area which then stopped and the response got better but now it is rough again also the temp gauge is going up to around 90 which all points to (i'm told) a Lambda problem.
If (when) you clean the 4 cyl engines you must not get water into the area around the oil filler cap. Because the (embarrassing) plastic sheet on top of the engine on these models doesnt shut out water from entering plug holes 1-4 which are close to the oil filler cap. Most annoying. And not all Alfa workshops know either so when back from service you face the risk of filled plug holes...
And the engine misfires as a result...
If cleaning engine, then clean top cover with moist sponge NOT hose!!!
I sputtered home (Norway) from Paris last easter...
I had a similar problem on my 145. Equally simple fix.
It would often run rough & misfire slightly, as if the petrol was bad.
The problem was a dud sparkplug, and the small
misfire was probably due to the secondary spark plug igniting late (AFAIK on newer TS engines, the 2nd set of plugs fire half a turn of the crank later to burn any unburnt fuel and aid emissions) The first series of TS engines fired each pair at the same time)