V6 Intermittent Missfire + Down On Power
Still got problems with my missfiring V6. Still not sure what the problem is, although the car will begin to missfire at normal operating temperature. There are big flat spots all the way up the rev range, including low down the revs, and after a few minutes of running like this, the car will begin to run normal again - this whole process keeps repeating itself and its driving me mad.
I haven't got access to Alfadiag or any other diagnostic software, and being after Christmas as well I am a bit strapped for cash, just like all of us, so was hoping to kind of "self diagnose" the car - which is proving to be a bit difficult!
I have cleaned out the throttle butterfly earlier yesterday afternoon, this didn't make any difference at all, although it was pretty gummed up - I cleaned it with a small amount of air intake cleaner. I have also unplugged the air flow meter - this made no difference to how the car run - if anything, the car may have possibly run a little better from cold, although once the car had warmed up, the missfiring and flat spots came back. It is also worth mentioning as well that the red "injector" warning lamp is illuminated when the AFM is unplugged, but when it is reconnected the lamp goes out.
One other thing I have noticed is that the car generally has lost much of its power - very sluggish lower down the rev range, even when running without an apparent missfire. The idle speed also occasionally drops to being very lumpy (not erratic).
I have heard a few things about air flow meters and lambda sensors - I have never had a lambda sensor go wrong, so I am not sure what the symptomns of these are. I just don't want to part with £170 for an air flow meter, and find that this isn't the failing part!
It may be worth noting that all six plugs were changed last summer by myself, so it is extremely doubtful that these are failing! Any help would be greatly appreciated!
Alfa Romeo 156 3.0 V6 24v Lusso (2000)
Lancia Delta HF Turbo IE (1991) - Rust In Peace !