Car running rough during acceleration
My 2009 Elise seems to be running rough. This has been gradually getting worse in the past 2 months.
At full highway speed (120 km/hr or 75 mph) the engine seems smooth and the car revs at about 3600 rpm.
But between about 80 km/hr and 100 km/hr while reving at about 3000 rpm there is some roughness. At first I thought it might be due to a tire imbalance or maybe bad shocks but I am tending to think it is the engine.
I tried a few things and none seem to make much difference.
1) Fuel cleaner product
2) Water remover product
3) Octane boost product
4) New spark plugs
5) Octane 94 grade instead of 91
6) Tried PetroCanada instead of Shell
I would not mind taking it to the dealer but I don't think the problem is bad enough yet that they would be certain to observe and fix it.
Note that I did change my air filter about a year ago so I doubt that I'd need to replace that now.
2009 Saffron Elise
1986 Toyota Tercel - RIP Oct 20/2012