Having a recent issue with my 1987 M6. It starts fine, even when it's been sitting. But it sputters a bit when under load....only until it reaches operating temp. My immediate suspect is the ICV, but wanted to see if anyone had any other ideas before I dig in.
Thanks
M6 Sputter under load when cold
Moderators: GRNSHRK, ron, bfons
M6 Sputter under load when cold
'87 Dinan M6, Cinnabar/Lotus
'09 M3, Interlagos/Fox Red
'09 M3, Interlagos/Fox Red
Re: M6 Sputter under load when cold
other than being a potential site for air leaks (for unmetered air because it has hoses and potential leak sites) the ICV cannot affect running under load; all it does (even if it fails entirely) is affect how much air goes through the throttle butterflies and how much through the ICV; it should all be metered air either way and the fuelling should be matched to it. Air leaks (from the outside world to the inlet) are a different matter.
Rough running when cold (on a car with an O2 sensor and closed loop running) suggests to me that something is making the mixture too lean (or too rich possibly) during 'open loop' running i.e. before the O2 sensor heats up and starts working. Once the O2 sensor heats up it will control the fuelling and mask whatever faults you may have.
Very common problems are
- air leaks (unmetered air) and/or
- failed CTS and/or
- badly regulated fuel pressure
cheers
Rough running when cold (on a car with an O2 sensor and closed loop running) suggests to me that something is making the mixture too lean (or too rich possibly) during 'open loop' running i.e. before the O2 sensor heats up and starts working. Once the O2 sensor heats up it will control the fuelling and mask whatever faults you may have.
Very common problems are
- air leaks (unmetered air) and/or
- failed CTS and/or
- badly regulated fuel pressure
cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~