I have a 94 940 non turbo, what grade of fuel should i put in it? Im only asking because i just bought the car and i have a problem, when i take off from a stop the car bucks and chuggs really bad but not when it gets over 2K rpm and it also will not do it when i first start it up in the morning. I put mid grade (89 octane) in it the other day and it seemed to really help it, or it was just a coincidence.

it also seems to run better when the fuel level gets low... ehh, who knows.

 

Oh i also forgot, i had someone else drive it while i followed and when it was chugging, it smelled like it was running super rich!

 

I'd try replacing the fuel pressure regulator first