Car seems strangled after 4k

  1. Frequent Poster Joined: Apr 2010 Nottm. Posts: 924 Focus ST2 ASBO
    #1
    99' VTR

    pulls really well and changing at just 4k still sees resutls

    Its just any more than 4k and the engines screaming, really struggles to go past it

    Its got a 6" K&N open filter with a 76mm ID to 62mm ID reducer pipe


    We thought fueling... not enough fuel to mix with the ammout of air at that RPM, BUT surely the ECU would ajust the ratio?

    Injectors being too small IMO is out of the question, people only fit larger ones due to boost (?) may be wrong though...

    any help?
  2. Established Member Joined: Apr 2010 Posts: 1016
    #2
    Fit a new fuel filter for the sake of a few quid and carry out a service. A fuel filter in need of being replaced usually give this symptom.