my 2007 325i has a habit off running weird, ticks over fine blip the throttle and engine runs lumpy, feels like running on 4-5 cylinders and popping through the exhaust rev engine to 200-300 revs runs fine again, read codes cyl 1 misfire and map sensor changed plugs and coils on all 6 to be sure, still the same reread codes cyl 1 misfire was recommended changing injector so changed for new one, coded it in ran fine until i blipped the accelerator back to rough running, rev to 200-3000 runs fine again, no engine light or codes now, using ISTA, any help appreciated,

Hi Kev

Welcome to the Forum

With ISTA you have the right tool it should let you get to the bottom of the problem. Have you checked fuel pressure could be a dodgy pressure sensor? Checked all Vacuum lines and hoses on the inlet side to make sure there are no air leaks ? Carried out a smooth running test using ISTA ? Throttle body OK ?

Just thinking out loud for things that could give a mis-fire

Hope this helps

Dave

Have done a smoke test and no leaks until it gets to the valve on top of the rocker cover, very new to ISTA but not diagnostics so still working through it, will try again tomorrow evening as England playing tonight. thanks