Stumbling Idle Cold Start Fuel Injectors Cleaned | FerrariChat

Stumbling Idle Cold Start Fuel Injectors Cleaned

Discussion in '360/430' started by Pete Schweaty, Sep 30, 2025 at 1:53 PM.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Pete Schweaty

    Pete Schweaty Formula Junior

    Joined:
    May 21, 2014
    Messages:
    307
    Hey all, I just wanted to put it here for search purposes in case anyone has the same issue in the future. Several months ago, I noticed that after the car (2005 f430) had sat overnight, it would stumble on startup for about 5 seconds. The idle would search up and down (almost like a gallop). It would then settle down before the CEL light went off. It would only do it if I started the car after it had been sitting for about 12 plus hours. At the suggestion of someone here, I pulled the injectors and had them cleaned and flow tested. I was disappointed when they all passed and didn't drip during the test as I thought I would have the same issue upon reinstallation. Fortunately, whatever the issue was, the cleaning (or replacing all the o rings) fixed it. Its been about a week and the car fires up and idles perfectly every time now. It only cost about $20 per injector and a local shop did it in about 6 hours. If you come across a similar problem, take a look at your injectors!

    Image Unavailable, Please Login
     
    AandSC likes this.
  2. flash32

    flash32 F1 Veteran

    Joined:
    Aug 22, 2008
    Messages:
    7,115
    Location:
    Central NJ
    Full Name:
    Dominick
    Good to hear ..but could it have been the throttle body relearn that made the difference
     
    Pete Schweaty likes this.
  3. Pete Schweaty

    Pete Schweaty Formula Junior

    Joined:
    May 21, 2014
    Messages:
    307
    Does that happen automatically when you unplug the injectors? Also, would it only happen the first start of the day? The cold start condition didn't seem to cause it, it would only happen if it sat overnight or for more than about 24 hours.
     
  4. flash32

    flash32 F1 Veteran

    Joined:
    Aug 22, 2008
    Messages:
    7,115
    Location:
    Central NJ
    Full Name:
    Dominick
    The ECU relearns since the battery is disconnected
    Did you disconnect battery to remove injectors..or use shut off
     

Share This Page