Rough idle, misfire, wants to die

[Sach_UK]

Hi i have a g 1989 325i cabby preface which was running fine for a while after a small service, new maf, new idle control valve, new intake boots which then finally brought the idle down correctly. Yesterday i thought i had perfected the engine side of things, fired her up today and she started to rough idle, misfire and shook the whole cabin quite roughly. it spluttered between 100-800 rpm. Any ideas what to look at first? thanks

[JF008]

Did you use a BMW maf or a generic one? Had that problem with the cheap stuff... and vacuum leaks.

[Sach_UK]

BMW maf mate

[Manni198]

i know this dumb but have u got petrol in it

[JF008]

Have you solved your issue? you can try disconnecting the MAF to see if its the cause of the problem..

[oomz1975]

Check all hoses are still fitted on tightly, no air leaks etc.

[Speedtouch]

Try disconnecting the ECU or battery and leaving it for an hour or so to reset the ECU. Then let it idle for at least 10 minutes, switch off, then go for a drive throughout the rev range.

This ensures base idle settings are learnt and full data transfer from the EPROM chip.