The Plot Thickens

Discussion in '8-valve' started by I'mMarkTwoToo, Oct 5, 2018.

  1. I'mMarkTwoToo Forum Member

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    Ok, so I'm trying to sort out the rough running/idling and so far I have cleaned out the ISV (buzzing nicely), cleaned out the throttle bodies, replaced the UFO and bung, checked vacuum hoses, removed the blue sensor (engine splutters and dies - cheers Tristan and rubjonny) and still nothing has made much, if any difference. But, what I have just found is that there are no hoses running to/from my airbox, other than the intake hose and the blue/red wire on my MAF connector is broken. I've also noticed that the oil temp on the MFA only ever says "160" regardless. Could all or some of this be contributing towards the dodgy running - I'm guessing the MAF is the biggest candidate?[​IMG]
     
  2. Tristan Forum Junkie

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    Definitely fix the maf, rather than splice , I'd get some new power timer connections and repin it. Though a good splice is fine ,just not as neat .
    Also check the pins aren't corroded on the maf .

    The hoses to your airbox, other than the big one, are the small plastic vac lines in the picture. Only the top one goes to the engine, to a Tee piece near the fuel pressure reg.
    Are you sure the blanking bung on the throttle body is intact ? Behind it? And that the vac line for the mfa is OK?
    Plugs?
    Timing?
    Idle fuel mixture?
     
  3. I'mMarkTwoToo Forum Member

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    I'm fortunate in that I work with aircraft avionics guys so I will call in a favour to get that wire sorted. On the airbox there is a bloody great hole on the bottom towards the front of the car and another facing the bulkhead, I opened the 'box and there is a big plastic hinged flap inside behind where the rear facing hole is.

    There is a hard bung in a small length of hose attached to the rear of the throttle body.

    New plugs were fitted at the MOT about three weeks ago because it wouldnt start, the garage had to mess with the mixture as it was reading "between 7&9", they were in the process of doing the timing at the time I was there to collect the car.
     
  4. Tristan Forum Junkie

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    Aha. the holes , one is supposed to have a pipe heading in the direction of the exhaust mani , to take in warm air to help cold running , the other should have a trumpet type effect that goes to the headlight area, that's where air gets in .
     
  5. Tristan Forum Junkie

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    Between 7 and 9... Ignition advance in degrees , maybe .. But nothing in the fuel mix sounds like that . 1.8 % CO maybe .
     
  6. I'mMarkTwoToo Forum Member

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    Yep, nowt there, just holes. More bits missing then.
     
  7. I'mMarkTwoToo Forum Member

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    Found out that Team Mulisha, who run mk2's in various states of looniness including an R32 engined 572bhp monster are based in the workshop behind my hangar. I think I'll have to be paying them a visit on Monday!
     
  8. rubjonny

    rubjonny Administrator Admin

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    the warm air system doesnt make any difference that I've noticed, mine has been disconnected since 2005! for the front hose people pull the snorkel out for a bit more induction noise, if you want it like oem then hunt around for the plastic shroud that fits aorund the driver headlight. you'll probably find the bottom half is still there just need to get the top part and maybe the snorkel bit too if missing

    oil temp display will be unrelated to running issues, all it will be is either the little white sensor in the oil filter is dead or the green/black wire has fallen off it and earthed out
     
  9. I'mMarkTwoToo Forum Member

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    Cheers once again RJ. I've read about removing the snorkel but wasn't sure what it was as I didn't have one to look for! On top of the MAF wire being broken, I found another broken wire going to the throttle harness connector (?) on top (or could be behind, I can't remember) the throttle body. Should be two wires going in but I only have one and a half so hopefully I'm getting close to finding the problem and solution. Luckily one of the avionics guys at work said he will sort them both out for me.
     
  10. rubjonny

    rubjonny Administrator Admin

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    sounds like the idle/wot switch plug to me, common for them to snap.

    junior/power timer pin same as the AFM pin you need to fix though the idle switch plug wires need a wire seal on which you slip down the wire, crimp pin on, then slide seal back up to cover rear of the terminal. The plug itself is junior/power timer 2 pin as well, industry standard so easy to get a new one if you need to
     
  11. I'mMarkTwoToo Forum Member

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    I'll pass all that on - went way over my head. I did notice that when I press the WOT switch the revs would just rise instead of falling.
     
  12. Tristan Forum Junkie

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    https://goo.gl/images/QsvCqv

    And a rubber boot like what newer models use helps support the wires .
    https://goo.gl/images/NiomCt
     
  13. I'mMarkTwoToo Forum Member

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    That's fantastic, cheers Tristan. One way or another I'm determined to get this bloody thing sorted and your help is fantastic. I've been a member of forums in the past and they seem to be used for slagging people off or used as an opportunity to show off and make others feel inferior or stupid. How I miss those forums..Only kidding, this is exactly the kind of help I need and really is appreciated.
     
  14. Tristan Forum Junkie

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    Cgti is THE place for technical support .
    A lot of serious knowledge here . We don't say an awful lot , but usually when someone like Rj or Toyotec or TonyB etc speaks, it's worth paying attention.
     
    I'mMarkTwoToo likes this.
  15. valvemiester

    valvemiester Paid Member Paid Member

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    I had the wiring on the WOT break, car idle was fine but throttle was on / off like a tap when either accelerating or backing off the accelerator not smooth at all, sorted the broken wiring and all was fine (mk2 GTi 2l 8v)
     
  16. rubjonny

    rubjonny Administrator Admin

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    you would just carefully dig the boots out of the old terminal usually, if your mate has a set of good release tools the original plug housing can be reused too though once the wires have been tugged out it can be a real hassle to get the pins out.

    probably easier to cut a donor plug off a scrappy car and graft in, as now wires snapped you may find theres not enough length on the originals anyway. or you might want to pull the ecu loom out and strip it down completely for full repair right back to ecu, since you have at least 3 wire breaks that you know of this might be the best plan?

    with the digi its handy as the ecu loom splits off from the main harness in the scuttle and at the coil plug then comes out without havign to go back to the fusebox. then you can strip it for repair, or drop in a new loom which is in better nick. only thing if you go that route is CE1 and CE2 digi looms differ at the connecting plugs in the scuttle, ce1 has 2 spade plugs and ce2 has a 5 pin timer plug.

    Its easy enough to adapt either way since the wire colours match up, just the CE1 ecu looms have 1 less wire to the fusebox as the injector and ecu power are fed from the same black/yellow wire and on the CE2 loom they have separate red/black to fusebox for injector power. you can ignore the ce2 red/white its lambda heater power and is unused for UK spec
     
  17. I'mMarkTwoToo Forum Member

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    You were dead right rubjonny. The wiring is in such poor condition and so brittle it was just breaking away. He managed to do a temporary splice on the wires tonight before it got dark and the engine was idling much better but kept dropping and rising between about 800 and 1200 rpm. I did order up a couple of those junior 2 pin plugs so he will fit them as soon as they arrive. But I think he was surprised but just how poor the wiring is, not the condition as much as the lack of care that has been taken by the last owner over the amount of electrical tape that has been used. He also noticed that the bonding lead on the side of the engine above the gearbox had been cut to about an inch in length and went nowhere.
     

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