Hi My 318i is stumbling and back firing with little power. It has been stored for about two years without use. So far I've checked for vacuum leaks, cleaned the Idle control valve and added new gas. This has helped the idle somewhat. I also checked and cleaned the spark plugs; they a look good and all the same.
In the driveway it idles rough just until you give it gas. Then it smooths out. I do get back firing and missing when driving and also get backfires if its allowed to idle in the drive way for a while. No earth shattering backfires just relatively minior or quieter ones.
I also unhooked the throttle contro sensor and it makes no difference to the idle.
Where should I go and what should I do next?