Hunting at idle. Guzzling petrol. 1.8ts
I am new to Alfa but totally hooked on these cars. I have a 98 model 156, 1,8ts. I am getting terrible fuel economy and trying to rectify this. First test showed 1.3 L/10klm (21MPG). Changed the plugs to NKG Platinum, new air filter and made sure there were no issues in the air intake. Next test showed a slight improvement but still way too high at 1L/10klms (27 MPG). Mostly highway driving
There is a sooty deposit around the exhaust pipe so I assume it is running rich. Engine performance is ok but it does “hunt” at idle. Going from 900 to 1300 then sometimes dropping down to 500. If I really gun it, it feels a bit sluggish up to 3000 rpm but then gives a surge of power from 3000 up.
Today I replaced the MAF. Unable to do a good test drive because of torrential rain but I did feel it had more punch before 3000 rpm and still the surge of power after. It still hunts at idle though.
Next up is the coolant sensor. It might be sending a signal the ECU that the engine is cold so it might be running chocked.
If that does not help then I will look at the oxygen sensor on the exhaust.
Any other tips would be most welcome.