fluffy / misfire especially when cold
Hi - I'm in Auckland, NZ and have a 1998 Forester S/20. I've had it about 3 months and cannot get rid of the fluffy / misfire that is especially bad when cold. It had a low compression in 1 cyl that was diagnosed as the problem, so that head was refurbished. No improvement!! Winger Subaru can't work it out but suggest using higher octane fuel. Local mechanic is not a specialist but sensible, has conceded defeat. I have been guilty of putting 91ron in the tank and the fluffiness is def worse on low octane - so I am sticking to 95+ and that helps but its just masking the problem. Auto-sparkie has checked everything he can, and mechanic has now had injectors checked. We love the car but can't live with its misfire. The symptoms are reasonably subtle when tootling about but very obvious with four up, up a hill or under load, when cold. Can anyone help as I don't want to start buying parts in order to try and eliminate problems without knowing what it is. Help!!