Problem with power loss

Discussion in 'VW Mk4 Jetta, Golf, New Beetle, Passat TDI forum' started by tomka580, Sep 3, 2017.

  1. tomka580

    tomka580 New Member

    Joined:
    Apr 27, 2017
    Messages:
    9
    Car:
    VW GOLF MK4 1998
    Location:
    Lithuania
    Hey all, so I already had thread on this forum few months ago, but I still have the same problem.So firstly I have 1.9 TDI 81kw (110hp) Gofl IV with AHF engine.The problem is that car doesn't have that "boost" felling when I floor acceleration pedal , but some times it does.When I start the car sometimes it runs great for first minutes or even seconds ( I mean if I start driving from first to second and third gear everything is ok but after I stop and start drive again there is no more "boost" ) I don't think that it could be limp mode cause I don't get any check lights or error codes ( after checking with VCDS ) , also if I try to start engine again while driving nothing changes.Anyway if I'm driving steady on for example 40-60km/h on third gear and if I press gently acceleration I feel that boost and everytihng seems ok, but if I press it hard, speed increases slow enough, and I don't feel any boost even if it reaches more than 3k rmp.The turbo is restored and no more than 6000km are done with restored turbo.Also I have done logs which I will add below and turbo seems to run good.So far what I have done:

    1. Checked turbo with VCDS and It seems good for me:


    2. There was a MAF sensor fault, so I bought and used sensor, no fault anymore but still same problem with power.Also I tried that used MAF on my friends car and he gave me to try his MAF , no changes for me and for him so my used MAF is totally fine I guess. MAF check:


    3. I have checked start of injection ( TDI Timing ), it was slightly retarded so I made it slightly advanced using tutorial on ross-tech site, still no difference.
    4. Checked vacuum lines , and found one bad and few which seems to be quite old, so I replaced them , also some lines were new , I guess previous owner replaced them.So still no difference in power, but now car shut offs better cause that bad vacuum line was leading to anti shudder valve.
    5. Checked N75 with VCDS and it seems to be good but I still believe that this can be a problem, maybe it stucks inside when I start driving and turbo starts working, can it be ? Anyway the turbo actuator moves good when I start the car.Also I tried to swap N75 with N18 , but no difference, maybe N18 could be also bad :D , my EGR is deleted as I know , so maybe it was deleted because N18 was not working ? I really don't know cause I forgot to ask previous owner about EGR , but the vacuum line to EGR is clogged up with screw.
    6. Checked group 13 in engine, not sure what it means, but searched in forums and in my opinion is not very good ? https://i.imgur.com/DLBcuIO.png this is when engine is cold , and this when engine is 90C https://i.imgur.com/RXCVg0K.png
    7. Removed fuel pump ( from fuel tank ) and cleaned that filter inside ( not sure how it calls ) anyway it seemed be quite clear.
    8. Changed fuel , air filters.

    So I think I wrote everything.I don't get any fault codes , just got MAF long time ago but as I said I changed it, cause with old MAF sometimes it could't even go above 60km/h.Any more suggestions what can I try ? Cause I really don't know what can I do more.I really don't have much money for a specialist so I'm trying to find out everything by myself :)

    Also forgot to mention that I have problem that car takes little bit more time to start up when engine is warm.Still not searching what can cause this , but few people said that It could be starter ( also found in other forums ) but also can be fuel injection pump.Maybe this can be a problem which can also cause power loss ??
     
    Last edited: Sep 3, 2017
  2. mgoff5000

    mgoff5000 Member

    Joined:
    Feb 27, 2012
    Messages:
    226
    Car:
    2000 Jetta 5-spd, 2004 Passat Wagon
    Location:
    SF Bay Area
    Mods:
    Jetta is on H&R Sport/Koni Yellows, Skid plates on Jetta/Passat, BSD and cam replaced on Passat
    Great post! Is the Block 11 log from a trip when you experienced the problem? If not, that's the next thing to get in my opinion. If you can confirm with VCDS that the problem is boost pressure then you can start narrowing down on whether it's a leak, faulty turbo etc.
     
  3. tomka580

    tomka580 New Member

    Joined:
    Apr 27, 2017
    Messages:
    9
    Car:
    VW GOLF MK4 1998
    Location:
    Lithuania
    Yea, just one day I took my free time to do that log, I found long enough road and just recorded video log cause I was driving alone, so yea log seems good to me , but there still was no boost, I just started from first , to second and third gear going to almost red line with third gear as I remember.
     
  4. mgoff5000

    mgoff5000 Member

    Joined:
    Feb 27, 2012
    Messages:
    226
    Car:
    2000 Jetta 5-spd, 2004 Passat Wagon
    Location:
    SF Bay Area
    Mods:
    Jetta is on H&R Sport/Koni Yellows, Skid plates on Jetta/Passat, BSD and cam replaced on Passat
    Let's start with what you mean by "boost". VCDS shows that you are getting specified pressure in both acceleration runs. On the forum here boost=pressure for the most part.
     
    tomka580 likes this.
  5. tomka580

    tomka580 New Member

    Joined:
    Apr 27, 2017
    Messages:
    9
    Car:
    VW GOLF MK4 1998
    Location:
    Lithuania
    I mean that I can't feel that "boost" feeling when I press acceleration pedal all the way down, I tried driving my friends 1.9 TDI 66kw ALH , even it has less power , I could feel that "boost" at second gear and little bit at third.I also have Opel Astra G 2.0 DI with 60kw ( 80hp ) and I still can feel that little boost while I start hard acceleration, but I can't feel this with my Golf.I'm not an expert but I still feel that something is wrong with my car's power and I really can't find out what is it :D

    Btw saying "boost" I mean that felling when you fell pull back to the seat , I don't know how to explain good cause my english skills are not the best :D
     
    Last edited: Sep 5, 2017
  6. mgoff5000

    mgoff5000 Member

    Joined:
    Feb 27, 2012
    Messages:
    226
    Car:
    2000 Jetta 5-spd, 2004 Passat Wagon
    Location:
    SF Bay Area
    Mods:
    Jetta is on H&R Sport/Koni Yellows, Skid plates on Jetta/Passat, BSD and cam replaced on Passat

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