1988 Gti 16v Rough Running Issues - Found a couple of things - Need help!

Discussion in '16-valve' started by Gazzmondo, Feb 18, 2016.

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  1. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    A couple of discoveries tonight...
    The rubber that holds the lift pump into the housing is perished and the return hose looks very thin.
    [​IMG]
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    [​IMG]

    Also noticed that I have a dodgy earth which affects the ISV. If I wiggle the earth wire to the engine, the note of the ISV changes? It actually stopped buzzing altogether one time, as I was moving the wire about.
    There's now a high pitched noise coming from the under car fuel pump or the fuel accumulator, not sure which one it is?
    I'll upload a video later as I'm having problems doing it at the minute.
     
    Gazzmondo, Jun 22, 2016
    #121
  2. rubjonny

    rubjonny Administrator Staff Member Admin

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    looks like you have found the issue, with the damaged lifter pump pipe would affect its ability to keep then main pump fed. the return doesn't matter so much but obv you should sort it. This probably explains the high pitched noise from the main pump under the car, they dont like running dry!

    the earth on the head you are messing with is probably the one for the ISV control unit, theres one for the ecu there as well so be sure all the earth rings are clean, tight and well crimped
     
    rubjonny, Jun 23, 2016
    #122
  3. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Thanks John (rubjonny). As usual, you are a great source of knowledge (certainly most of mine).
    Concerning the earths. They've been electrical taped, doesn't look the best. Also, the earth wires are very stiff with little give in them?
    Got a very useful contact for a replacement of the rubber connector (Cohline in tank fuel hose) from member trackdaygtimk2.
    Thanks!
     
    Gazzmondo, Jun 23, 2016
    #123
  4. rubjonny

    rubjonny Administrator Staff Member Admin

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    yeah they get like that with age and/or oil contamination. best way to repair is cut back till you find decent coper and soft insulation and splice fresh wire in (well, best way is replace the whole wire end to end, but I doubt you fancy that option :lol:)
     
    rubjonny, Jun 23, 2016
    #124
  5. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    You guess right.
     
    Gazzmondo, Jun 23, 2016
    #125
  6. beetie

    beetie Forum Member

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    Sorry been away. If you need any bits just give me a shout as I still have them. Obviously try all the cheaper easier bits 1st.
    I remember my isv wires had broke at the plug at the isv had to pull the rubber back and reconnect it.
     
    beetie, Jun 25, 2016
    #126
  7. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Replaced the perished rubbers on the lift pump and replaced the dodgy earth. Car starts and ticks over, had to wind the tick over screw out, for it to tick over on its own. Leaned out the CO as best I could but it's still a bit lumpy. Still got hot start issues though? Takes a good few turns to get going, splutters into life eventually. Could the fuel accumulator still be shot? Like I've said in the past, turned the car off then wound out the screw in the back and no fuel comes out? So does this mean it's ok, or could it be defective still?
     
    Last edited: Jun 26, 2016
    Gazzmondo, Jun 26, 2016
    #127
  8. rubjonny

    rubjonny Administrator Staff Member Admin

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    it might be the non-return valve in the fuel pump, best bet now is get the fuel pressures checked and if good have it tuned properly I recon
     
    rubjonny, Jun 27, 2016
    #128
  9. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    I've put a brand new, non return valve and washers on?
     
    Gazzmondo, Jun 27, 2016
    #129
  10. rubjonny

    rubjonny Administrator Staff Member Admin

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    right it should be ok then, could be knackered out the box tho. as i say best bet is get your pressures checked now, this will show you right away if you have a problem with the residual pressure being lost or if its some other problem.

    another potential cause is worn o'rings in the fuel pressure regulator:
    vwgolfmk1.org.uk/forum/index.php?page=topicview&id=technical%2Ffuel-systems-and_3%2Fk-jet-not-holding
     
    rubjonny, Jun 27, 2016
    #130
    Gazzmondo likes this.
  11. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    I'll check it out... and get my fuel pressure checked!
     
    Gazzmondo, Jun 27, 2016
    #131
  12. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Does the fuel pressure regulator just unscrew from the fuel distributor on the metering head? Tried a spanner on it but mine is in really tight. I'm guessing that I need to release the pressure somehow, first?
     
    Last edited: Jun 29, 2016
    Gazzmondo, Jun 29, 2016
    #132
  13. rubjonny

    rubjonny Administrator Staff Member Admin

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    yes it should unscrew, pull the fuel relay while its running to get the worst of the fuel pressure released, then leave it as long as you can preferably overnight. even after all that hold a rag over it before you crack it loose just in case!
     
    rubjonny, Jul 4, 2016
    #133
  14. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Thanks.
     
    Gazzmondo, Jul 4, 2016
    #134
  15. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Which one is the fuel pump relay. Says slot 5 on the cover, but that can't be right?

    [​IMG]
     
    Gazzmondo, Jul 5, 2016
    #135
  16. rubjonny

    rubjonny Administrator Staff Member Admin

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    fuse #5 is for fuel pump, relay in slot 2 is the fuel relay ;)
     
    rubjonny, Jul 6, 2016
    #136
  17. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    Cheers!
    Just another thought... Although the fuel pump primes and buzzes while the car is running, could the fuel pump relay still be faulty and causing a hot start problem?
     
    Last edited: Jul 6, 2016
    Gazzmondo, Jul 6, 2016
    #137
  18. TOM-UK

    Tom-uk Paid Member Paid Member

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    wouldnt have thought so mate, the realys job is just to flick the pump on on the ignition. I think they normally fail by sticking closed so that the fuel pump is always running. there should be no temperature dependance so as long as when you key on for a hot start you can hear the pump priming then its not the relay
     
    Tom-uk, Jul 6, 2016
    #138
  19. rubjonny

    rubjonny Administrator Staff Member Admin

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    they can fail and start breaking down especially as they heat up, easy test though swap the 18 relay into slot 2 and see if it fires up ok. if just as bad then fuel relay is unlikely to be the problem. on mine i had intermittent pump fault which ended up being fusebox damage in the end, wigglign the relay woudl sometimes sort it but after closer inspection I foudn the fuel fuse had melted in the socket...
     
    rubjonny, Jul 6, 2016
    #139
  20. Gazzmondo

    Gazzmondo Paid Member Paid Member

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    I've noticed that there's oil leaking from under the distributor and dripping onto the top of the gearbox. There's also oil in the plug that's on the side of the distributor.
    There's some oil in the cap as well.
    [​IMG]
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    [​IMG]
     
    Gazzmondo, Jul 6, 2016
    #140
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