so my car started acting up about a month ago. I'm having a misfiring issue. It only does it at idle or at lower rpms. Most of the time it happens when i'm at a red light. When I'm sitting there, it will be idling fine, then all of a sudden the rpms will drop and it will run really rough. almost sounds like its a boxer engine or something..Sometimes it goes away when i give a quick blip of the throttle but most of the time i will have to shut it off, wait a few seconds and re start it. then it will run fine.. heres what I've tried so far.. fuel filter, new plugs, cleaned icv and mass air sensor. did seafoam. cleaned throttle body. I am getting really annoyed, maybe you guys have some ideas? any help would be appreciated
I personally wouldn't trust just cleaning the ICV, but that is just me.
There is also the throttle position sensor to consider.
A vacuum leak is another one.
If it's really a misfire then check your coil packs since you already replaced the plugs.
is the check engine light coming on? If so. swap out plug, coil, and fuel injector on that cylinder.
My rpms would drop here and there at idle, it would almost make the car stall. i was told to check the idc and this and that, but in the end it ended up being a bad Throttle positioning sensor, that didn't throw a cel until it decided not to work anymore.
-97 ///M3-R.I.P.. 01 330ci-Sold.. 96 S/C ///M3-Sold.. 03 530i.. 93 Vigor-
I had same exact problem recently.. Ended up being the upper chain tensioner
Check your coil boots, regap plugs, clean ICV.
1997 Arctic Silver/Black M3
CES Stage IV (651rwhp/615rwtq @ 24 psi)
1999 Techno Violet/Dove M3
Auto/Convertible and staying stock!
thanks guys, those are all really good ideas. I think the next step is to swap coil packs and see if the misfire follows to that cylinder. ill have to see if I can get a code scanner/reset tool...also changing that throttle pos sensor doesn't sound like a bad idea. thanks again for your input guys
ok, here are the codes that came up with the code reader....
p1250-fuel pressure regulator control fault
p0300- pcm has determined that random misfires have occured
p0304- misfire cyl 4
p0305 -misfire cyl 5
p0306 -misfire cyl 6
p0155- o2 sensor bank 2 sensor 1
p0161- o2 sensor bank 2 sensor 2
Ok, lets go down the list. Seriously.
Fuel Pressure, underload and @ idle.
How old are the plugs?
Dead packs?
Vaccumm leak?
Broken ICV
Z3 - S50 - OBD2 - Smog Legal - 6 Speed - 3.46 - Anthracite
98' With Bolt-ons......pics. http://forums.bimmerforums.com/forum....php?t=1075182
o2 sensor?
96 320i Touring
98 Z3 2.8 Roadster
01 PY M Coupe
96 Z3 1.9 - DASC
95 318ti Clubsport
94 Miata M-Edition
13 smart fortwo
O2 sensors as a start. Replace both pre-cat sensors. They're expensive (~$100), but if you don't do them now (when they need to be done) you'll end you replacing all four and your cats.
I'd check your coilpacks/boots too, but strictly based upon your codes, it's likely all your problems are coming from your O2 sensors.
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