Starts, but won't tickover

Discussion in 'Mech Tech' started by Betty the Bay, Apr 20, 2019.

  1. Up in Scotland and the old girl's refusing to tick over.
    When it happend after a service, the mechanic said a wire had come loose and he tighten the joint....trouble is I don't know where this connection was and a quick look doesn't show as my wires off again !
    Help !
  2. Poptop2

    Poptop2 Moderator

    Is it the one on the right of the carb. The choke wire. If you look to the right of the carb from the back at the side should be a brown wire connnexted to a spade connector under a slight round bump
    Betty the Bay likes this.
  3. If you can start it but it won't idle then likely your idle solenoid connection has come off. This is at the back left of your left hand carb.
    snotty, Betty the Bay and 3901mick like this.
  4. Would that be this one ?[​IMG]

    Sent from my SM-J330FN using Tapatalk
  5. When the carbs were refurbished, the guy did put a note in saying that he had needed to silicone a part.
    This looks to be that part....if it's come a bit loose could that be the issue ?
  6. That solenoid is the one. What it's got is an electrically operated mushroom valve. Air feeds from the air filter through that rubber elbow into the idle system, but if the valve closes no air gets in. It shouldn't need any sealant but if the mechanic has overdone it that could block the flow I guess.
  7. It's a 2L.
    Wires to both sides of carbs are predominately black.
    Poptop2 likes this.
  8. Dubs

    Dubs Sponsor

    It looks like the mechanic has had to silicone it because the threads have been stripped, which is not uncommon tbh.

    If it is letting in air there, it could be your problem, as could the solenoid being faulty, or not getting 12v.

    Carefully see if it feels secure, check it's got 12v, and then try spraying wd40 round the join while it's running to check for air leaks. Also check all the other black wires going to the carbs.

    Also, check all the black rubber elbows on the carbs and balance pipe / servo pipe for air leaks while you are at it.

    Edit... it's best to spray the wd40 when the engine isn't baking hot, for obvious reasons...
    Betty the Bay likes this.
  9. I'd also add that the wire to the solenoid has been wired unconventionally (though mine is also like that). The wires should be black but there originally were separate wires to left and right hand carbs. The left hand carb wire normally starts at the coil and runs to the choke, main fuel cut off solenoid, idle enrichment unit, and idle solenoid. The right hand carb has a separate wire to choke and fuel cut off solenoid, but it's possible to daisy chain the lot with only one connection to the coil.
    Betty the Bay likes this.
  10. Poptop2

    Poptop2 Moderator

    Sorry. I presumed 1600.
  11. Update.....had Green Flag out.
    He thinks the problem lies with the solenoid ( prompted by me reading him the comments on here. )
    Getting 13v approx at solenoid, so if been to source some brake cleaner and silicone sealant....going to clean it up, unthread a couple of turns and carefully put some sealant on the threads before tighten it all up.
    Will report back tomorrow.

    Thanks for all replies.
    theBusmonkey and CollyP like this.
  12. Don’t forget the body of the solenoid needs to be grounded to the engine case, or it won’t function. Take it out and test it across your battery. If it pulls in, the problem’s the sealant.
    Dubs and andyv like this.
  13. Will see what occurs in the morning when I start her .... good call though!
  14. The other naff way to keep going is to tweak the throttle endstop so it speeds up the idle. But this cna be disconcerting if you are used to having engine braking.

    After that tweak, you might have to stall it if it diesels on after a long run when the carbon on the pistons is glowing red hot in places ( also a sign of maybe needing a proper tune up ). The solenoid is intended to kill it at idle with the ignition either on or off starving it of fuel.
  15. The Green Flag man did consider that, but thought it was best to address the obvious issues, although that might cure the hesitence when moving off at low speeds.
    It's been properly serviced before the holidays.
  16. Presuming it doesn't click when you reconnect the wire, you could test this just by sticking a screwdriver between the solenoid body (not the live terminal) and the body of the carb. If it clicks now that's the answer, and you can cure it with a temporary twist of wire to bridge the gap.

    BTW you were asking about setting the idle a bit back and I said to adjust the big right hand screw. How did that go? Also, when you had it serviced, did the carbs get synchronised?
    snotty likes this.
  17. Adjusted the tickover and it was "less bad" . Told the mechanic not to mess with the timing / carbs as she was running great.
    Turns out it was famous last words !
  18. Put some silicone sealant on last couple of threads of solenoid and tightened up... ran a wire from solenoid body to engine block as well.
    Started this morning and seems ok....difficult to tell with choke on and without disturbing campsite.
    Positive thinking... off out for a run and then further north tomorrow ... or recovery back to Yorkshire!
    theBusmonkey likes this.
  19. For positive read over optimistic!!
    Runs, or should I say doesn't run as yesterday... removed solenoid gave it a good clean and replaced it.... won't screw up tight, but put bit of sealant on last couple of threads.
    Leave it all to set and will try again after lunch.
    Assuming the worst, can you get new/replacement solenoid ?
  20. Yes you can get them from V W Heritage. But here's a thing that I just discovered. In an emergency it will run without the solenoid in at all if you block up the hole. I think the only likely downside is that it might "diesel" when you turn the engine off.

    As to how you'll stop it off, I looked in my nut and bolts collection and couldn't find anything the right size as it's a quite fine thread, so I stuck in a wooden dowel which did the trick. If you try this make sure you don't fit something that gets sucked into the works and makes it worse.
    Lasty and Betty the Bay like this.

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