PD BEW Poor fuel economy + smoke show while warming up

Discussion in 'VW Mk4 Jetta, Golf, New Beetle, Passat TDI forum' started by Mr. K, Apr 10, 2017.

  1. Mr. K

    Mr. K New Member

    Joined:
    Mar 5, 2017
    Messages:
    6
    Car:
    2006 VW Golf TDI
    Location:
    Quebecistan
    Hello,

    I've been working through a number of issues and symptoms with my 2006 Golf since a turbo change and head work. I've solved quite a few, but poor fuel economy and a smoke show while warming up are still there. The smoke is white and appears as the car is warming up to 90C, but lower in the temp range.

    So far, I have:
    - new lift pump
    - new fuel filter and thermo tee
    - ran a can of full-strength Diesel Purge through it
    - checked injector lash and it was OK
    - adjusted torsion value to +0.5. It was at -2.0 when I scanned it with VCDS. Yesterday I changed it to +1.0 (decal on the timing belt cover looks to say 1.2).

    I got a O2 sensor "P2196 - 000 - Signal too High (Rich) - Intermittent" code twice since I borrowed VCDS. Once at the initial scan and the mid-last week.

    Is that an indication that the O2 sensor is failing? What else should I check/replace?

    Thanks!
    Chris
     
  2. crsmp5

    crsmp5 Well-Known Member

    Joined:
    Feb 14, 2012
    Messages:
    1,550
    Car:
    85 kubvan
    how many miles on engine??

    how many miles on injector nozzles??

    compression of all 4 holes?

    what kinda fuel station you buy fuel from????

    how the cam lobes??

    car requires nice mist of fuel... if it is not then you get what you have on start up.. old worn nozzles, low compression, the actual fuel will each on own cause smoke like that...

    not all fuel is the same... some burns cleaner, others burn more dirty.. dirty fuel gives crappy milage vs good burning fuel...

    one station i used to visit gave 4mpg worse then other station... this is fill till not another drop can fit.. sad part.. the crappy mpg fuel performed better as in 0-60 good 1/2 sec faster.. quite a few months playing with this one...

    then a person borrowed my caddy once.. used truck stop fuel and god that shit sucked.. on start up i was a misquito spayer... took me refilling it 3 times from running it outta fuel where i had to reprime it to make the smoke go away.... so not all fuel is the same... and gotta wash out the bad before ya know if its resolved

    too bad i think a jerry can will not work on a pd... so any cheating on start up fuel is not possible
     
    Last edited: Apr 11, 2017
    Riccogolf likes this.
  3. Mr. K

    Mr. K New Member

    Joined:
    Mar 5, 2017
    Messages:
    6
    Car:
    2006 VW Golf TDI
    Location:
    Quebecistan
    The engine has 192k kms. The head was off to install new valve guides and seals, as they were found to be leaking when the turbo was removed. Cam apparently is OK.

    The car has good (if not better) power since the turbo change. I generally fill at the same station that gets a lot of traffic. Idle is smoother since resetting the torsion value. I just want my fuel economy back.
     
  4. Riccogolf

    Riccogolf New Member

    Joined:
    Nov 12, 2016
    Messages:
    9
    Car:
    VW, Golf Mk4 pd150 ARL, 2003
    Location:
    Chichester, uk
    This (poor mpg and smoke) sounds familiar...no answers I'm afraid just sharing experience....mine's a long story...104k miles, cam shaft goes...gets replaced and then has poor fuel economy, like 40% down, at least what computer is saying compared to pre new cam shaft....this fails again....new head this time, and amongst other things still poor mpg and smoky on cold start and poor running

    Various jobs done including 3 refurbed injectors and one new. Now, still white smoke on cold start but clears quite quickly though quantity varies every day, but clear usually in a minute or so, though still diesel smell from exhaust when warm....yeah, maybe it would as a diesel :) just more noticeable than I remember... fuel economy better now but still 10% down from pre chocolate cam...

    I'm currently doing a tank refill test (still a couple of weeks away) as I'm not convinced the computer mpg is accurate....I actually think the car is doing more mpg than ecu is saying....and although the car is running great, smooth idle, quiet, excellent power and acceleration, sometimes with just started cold engine and pulling away from junction there is momentary loss of power/ acceleration...It just feels like there's something amiss with fuel delivery and or ecu somewhere but nothing has been found...and general running around secondary roads etc if the computer is to be believed fuel economy still looks bad...

    Will report back when tank refilled.

    Good luck with it.
     
  5. Riccogolf

    Riccogolf New Member

    Joined:
    Nov 12, 2016
    Messages:
    9
    Car:
    VW, Golf Mk4 pd150 ARL, 2003
    Location:
    Chichester, uk
    so just as an update....you might want to check actual mpg by filling tank rather than relying on dash computer in case it is misreading, as mine appears to be doing, though I have no explanation as to why.

    Over 480 miles of mainly relatively short journeys from cold and occasional longer motorway driving my ecu was showing an average of 40.6mpg. this is way down on what I used to get. On filling the tank, I worked out an average of 46.4mpg....14% better than the ecu number.

    I have also compared the fuel consumption readings on VCDS (l/h), worked out mpg, and dash computer on several occasions and pretty much every time the VCDS number show 4-5% better fuel economy than the ecu dash average. Odd, as I imagined it would come from the same source.

    Any suggestions welcomed.
     

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