RPM unstable(shaky & jerky)when engine is cold

[danny_cha]

Hey bros,can anyone advises or give opinions for this problem.

When I started my engine in the morning or whenever is cold,the rpm is idling unstablely and when i started my journey ,its feel like a bit pulling your power and jerky until a while then its back to normal.

Rod did decarbonised and cleaned my trottle boby and even uses the fuel injector cleaner and its ok for about 2 weeks and now is back again.

and today when the engine is hot its happen a while till I gave a hard ram at nuetral gear and is normal again.

Did anyone faced this problem before and hopefully can get some informations for this problem,thanks

 

[clemgoh]

Re: RPM unstable(shaky & jerky)when engine is cold

Now sure what you have e46 - 318 or 320 etc... the 4 cylinder and older models are more prone to this problem. I had experienced this too with my 318... after 3 BMWs I know. A few things... a) the Mass Airflow Sensor needs cleaning or replacement b) Cam shaft sensor? c) Induction Coil? d) Spark Plugs? e) Get PML to set the tuning to a higher idle RPM instead? for some reason your rpm is below the factory setting? f) fuel filter replacement? g) spark cable? something like this order

 

[hetraa]

Re: RPM unstable(shaky & jerky)when engine is cold

shd be maf sensor, or exhaust o2 sensors need replacement...
sending wrong signals to ecu resulting in either overly rich or lean mixtures...

 

[danny_cha]

Re: RPM unstable(shaky & jerky)when engine is cold

Ya mine is E46 318 N42 engine.
I think probably its something related to the fuel issues.