i have a 320i, had it 6 months and i've got a bit of a flat spot on accelaration. top end is fine, idle is a pip rough, but not really. i've changed plugs, put fuel line cleaner in, new air filter (K&N). someone told me about the idle air stabliser valve. i got me a haynes manual and it says that if you disconnect the electrical connector, the revs should go up to 2000. and if they don't, you are to do some checks. first on the unit to test resistance across the terminals and i pass, then with the voltage coming into the unit, and i pass that too. so these test tell me the unit is fine, however when i disconnect it the revs stay the same. i think it is sticking closed, i opened it fully with a screw driver and DID NOT hook up the electrics, basically bypassing the valve and when i start up the revs jump from 1500 to 2000, like you are sitting there constantly rev rev rev revving. i gave her a little spin in this condition and sure enough the flat spot was not there, however the revs obviously didnt go below 1500, when i hoooked up the electrics again and sort of played with the throttle to keep it above 1500 and i had no flat spot anyway, my flat spot is right at the bottom of the revs. if i floor it it hesitates for about 1 second then kicks in and rips off. anybody got any ideas. and thank you if you take the time to read this and reply.
