My 98 528i started having idle issues the other day after I came out to start it and the battery was dead. I charged the battery and was able to start it, but it was idling really low 3-400rpm. This morning I came out and the battery was dead again. I was able to jump it and drive it and pick up a new battery for it. I replaced the battery, but the idle is still really low and rough.
I took out the ICV and cleaned it, it didn't look too bad. I put it all back together and it was no different, still low idle. I took it for about a 1 mile drive and now it won't even hold an idle as I was coming back, it runs fine if I keep my foot on the gas, but won't hold an idle itself.
Any thoughts? I disconnected the battery to see if maybe that will reset the ecu....maybe the ICV is just shot?
It just seems strange that its been fine before the battery went dead.
Any help is appreciated.