Type 4 2.0l cutting out.

Discussion in 'Mech Tech' started by FifeBay, Jul 10, 2019.

  1. Hi guys just got my bus registered this week so been for a couple of runs in her.

    She’s got a type 4 2.0 with twin Weber icts, today while our we went about 10miles with no problems then she cut out as I was parking her, since then every time I start and drive the engine last about 30 seconds to a minute or so before cutting out again she has power during the running and will fire up right away after cutting out.

    The bus is currently left at my mum and dads I’m planning to go and recheck the carb sync and idle set up but does anyone have anything else to check?

    She’s got plenty of fuel in her.
     
  2. You might want to check that fuel’s getting to the carbs properly. If it runs, then cuts out after a short while, might be that it’s used up a float-bowl’s worth of petrol that isn’t getting topped up.
     
    77 Westy and Dubs like this.
  3. Yeah very good point, it’s a new pump but it’s wired with relays to the starter for initial start then maybe not getting a signal from the alternator after that.
     
  4. Personally, I wouldn't rely on the alt signal to keep your pump going. Float chambers running dry is a possibility.
     
  5. Agreed. I’d have thought a better bet would have been to run the signal off the coil, but with power through a relay. You could, just as an experiment fit a clear fuel filter in the engine compartment so you can easily see if you’ve run dry.

    I had a similar cutting out problem some years ago, so fitted an electic pump and filter as a test. This demonstrated I was temporarily running dry but it wasn’t the pump at fault. It eventually turned out to be a blockage in the tank.
     
    FifeBay likes this.
  6. I think I’ve got one in the garage I’ll give it a try cheers.
     
  7. Stop calling it she and her and it might be more cooperative.

    Don’t run the pump off the coil, it’s safer taking the signal from the alternator so the pump stops if the engine stalls, but are you sure the pump is running once the engine starts?
     
  8. Haha you could be right.
    I don’t think my alternator is charging the battery I’m only get 12v at the batter when started I was expecting 14ish?
    Seems like this might be the issue.
     
  9. Does the alternator light come on when you turn the ignition on?
     
  10. No it doesn’t show at all.
     
  11. If the alternator light doesn’t come on the alternator won’t charge. Fix the alternator charging problem and you’ll probably find the cutting out problem has been fixed too. I doubt if the fuel pump is running once the engine starts and it was gravity fed until the fuel level dropped.

    Does the low oil pressure light work?
     
  12. Yeah the oil light works, I temporarily run it off the coil and the bus was fine no cutting out at all. So the problem looks to be with the alternator system some place.
    When should the light come on?
     
  13. Just like every car – the light comes on when you turn on the ignition and if the alternator is working it will go out when the engine is running.
     
    F_Pantos likes this.
  14. I don’t think that’s been coming On for a while when I think about it. First place to look would be if the lights working Like this:
    To test charge warning light on dash, pull the blue wire off the D+ terminal of the alternator.

    Turn ignition on and earth the blue wire on the engine case.

    If the battery charge light comes on, the circuit is good?
     
  15. But if the system is dry and awaiting a signal from the alternator, how will it get power to the pump without the engine running?

    Won’t the pump stop delivering once back pressure from the carbs triggers it.

    But I can see that it would be preferable to cut the power too if the engine stalls.
     
  16. You either put a priming switch in or wire it so a signal from the starter motor also activates the pump or better still use a tachometric relay that switches on when it recieves a signal from the coil that the engine is rotating.
     
    Dubs and 77 Westy like this.
  17. Either via a push button to prime the carbs or a second relay triggered when the starter motor is running.

    I use a fuel injection pump relay that runs the pump for a few seconds as soon as the ignition is on, and then it runs when it receives a pulse signal from the coil. If the engine stalls the coil pulse signal is lost and the pump stops.
     
    Dubs likes this.
  18. Ok so think I’ve solved the light issue. The D+ connection in the voltage regulator plug was loose so push back on and the light works as it should. The bus also now runs like it should.

    Still only getting 12.8v across the battery when running. Is this normal? Or could there still be a problem?
     
  19. Voltage across the battery with the engine running should be about to 14v. It’s not being charged at 12.8v.
     
  20. If it is a good but flat battery then you might see 12.8 volts for a bit.. but then it should rise to over 14 volts with reasonable rpm.
     
    77 Westy likes this.

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