BFH hesitancy on startup

Discussion in 'VR5, VR6 & Wx' started by G60Dub, Jul 20, 2018.

  1. G60Dub

    G60Dub Forum Member

    Joined:
    Oct 23, 2003
    Likes Received:
    29
    Location:
    Angus
    Not quite sure how to diagnose this hence the post. For the last month or so on cold start my BFH starts and idles fine but on pulling away in 1st runs rough and is hesitant for about 5 seconds or so then seems to right itself.

    Previously it's had about 3 tins of injector cleaner ran though it which made a noticeable difference to running and also fuel economy... if of course fuel economy is a thing on the 3.2

    Ran really well for a good while after that before this hesitancy manifested.

    Pump primes on door opening. Fuel pump was a new genuine VDO item that has done about 60k since being fitted. Fuel filter was replaced last week. All sensors except the crank sensor have been replaced with genuine items in the last 20k. New plugs just fitted and it still runs rough on a cold start.

    All coils (Beru) have 70-75k on them - how long do these coil-on-plug packages typically last?

    Dont have a digital storage scope to check the crank sensor is generating a clean signal.

    I've done some logging from cold using me7 logger but no misfires to speak of assuming that the odd register of 1 and then resetting to zero across random cylinders after a bit of time is normal.

    Not wishing to just chuck a couple of hundred notes at new coil packs all round unless they are likely past their best.

    Anyone any suggestions as need to get this nipped in the bud shortly?

    I believe one can work out injector duty cycle from the injector on time? If that is possible then I'll need to familiarise myself with the formula as I assume this would be a reasonable check to see if the fuel pump is supplying enough fuel on full load? Not really sure what else I can try.
     
    Last edited: Jul 20, 2018
  2. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,320
    Location:
    Creating Pfredstarke
    Unplug your MAF and try the test again after a soak.
     
  3. G60Dub

    G60Dub Forum Member

    Joined:
    Oct 23, 2003
    Likes Received:
    29
    Location:
    Angus
    Hi Eddie

    Thanks for your reply. Do you mean a good heat soak? The MAF has about 5k on it so hopefully not a faulty unit. I'll give your suggestion a try and post up how I get on.
     
  4. G60Dub

    G60Dub Forum Member

    Joined:
    Oct 23, 2003
    Likes Received:
    29
    Location:
    Angus
    Hi everyone.

    Not having a good couple of weeks with this - Unplugged the MAF when I returned from hols and it ran fine. Plugged the MAF back in and hard reset the ECU and all seemed well since.

    However, I've just had the Bank 2 wideband O2 fail on me today. These pair are only about ten months old - does anyone know what the legal warranty (if any) is on Bosch Widebands and if there is then where I can dig up the paperwork?
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice