would old petrol (like stuff thats been in the car for 12-18 months while in storage) casue spluttery revs, even under no load, sitting in neutral...?

yes it would as the RON will go down over time

ive put a gallon of fresh optimax in and its actually gone worse...?!?!

bear in mine that there was just enought in the tank before hand that the petrol light was on...

u may also have a lot of moisture in ur tank

could this attribute to the rich running (see other post)...?

id say its dwn to moisture please dont say you left it nearly empty for over a year if so definitely moisture, thats why they say atleast half a tank some fuel stabilizer and a few squirts of wd 40 before you put your car in storage, but im no expert could be something else

WD40

wd 40 gets rid of moisture trust me

yep completely empty (bar about a couple of litres) for nearly 2 years now

i just check when the last tiem it was actually driven

so, a full tank of fresh optimax, would cure it you reckon....? why would petrol with moisture absorbed into it make it run rich though...?