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Starting Troubles

Discussion in 'Fuel System & Electrics' started by Basil Bus, Apr 10, 2019.

  1. Basil Bus

    Basil Bus New Member

    Messages:
    15
    Location:
    Hobart
    Where do I start? Sorry if this is a bit long-winded.

    For years our bus ( '76 2L ) started brilliantly, regardless of the conditions. But we've had a series of sagas and this is the latest one. For a while now starting has been a bit "iffy". Sometimes it would burst into life, other times it would take quite a bit of cranking, even warm, sometimes the starter would bog down initially (as if the battery was flat) and then recover. It always did start eventually, but the problem seemed to be getting worse.

    Last weekend we had to go to something in the highlands. It was a cool morning and we just couldn't get the bus started. Afraid I may have flooded it I cranked the starter with throttle open but it showed no sign of firing. Eventually, I flattened the battery. I thought I'd jump start from the "domestic" battery (it's worked in the past) but, surprisingly, that would barely turn the engine over. We jump started from a neighbour's car and it started instantly.

    Thinking our battery may be on it's way out (it went flat rather quickly) we bought a new one on the way. When we stopped for lunch I installed it. The engine turned over beautifully but refused to fire. However, it bump-started immediately.

    The morning we were to return was cold and very damp and I flattened the battery trying to start the bus. We tried jump starting from a 4WD with heavy cables and it still showed no sign of firing. For some reason it would still only turn over very sluggishly. However, when we tried tow-starting it fired up without any trouble.

    On the 6 hour trip home I accidentally switched the motor off once and it re-started immediately. But on two occasions we stopped facing downhill and had to resort to bump-starting to get going again. Both times it fired up instantly. Once going it seemed to run normally. The next morning it wouldn't start first thing in the morning, but did start, with some effort later in the day.

    This morning (cool but not cold, and not damp) I flattened the battery again.

    Anybody got any idea what's going on?

    A couple of things I've found on my own, that may or may not have some bearing on this:

    I suspect the device that isolates the domestic battery from the starting battery may not isolate particularly well. I never had a lot of confidence in it. Perhaps I have been flattening both batteries at the same time and that's why I can't jump start from the domestic battery. I've disconnected the domestic battery for the moment.

    I noticed that, when stone cold, the RH choke butterfly was still half open whereas the LH one was shut. I took the choke off and tried closing the butterfly manually but I can't. It stops halfway. It just wont go any further and if I try it sticks and wont spring back. Any idea what the problem may be? I realise this would have affected the starting but does it explain why it wont start with the starter but starts easily otherwise?
     
  2. Barry

    Barry Well-Known Member

    Messages:
    3,583
    Location:
    Abbotsford NSW
    Is your bus carbs or FI?
    For the moment I will assume carbs

    My guess it’s an earthing issue.

    The fact that it bump starts easily as opposed to trying to jump start.

    Also the wiring in of the 2nd battery.
    That is an area to look for issue.

    The sluggish starting when trying to start normally or jumping

    The choke is an issue but not your main problem.
     
    oldman likes this.
  3. cbus

    cbus Well-Known Member

    Messages:
    11,700
    Location:
    sunshine coast
    Yep.
    Earth straps first suspect.
    Test by adding jumper leads from batt neg to bell housing.
    Even if strap from body to gearbox looks good it can run high resistance.
    Replace.

    Check battery to body strap as well
    Ensure clean surfaces where all straps contact body.
     
    oldman likes this.
  4. tintop

    tintop Well-Known Member

    Messages:
    459
    Location:
    Canberra
    as far as the choke goes, sometimes the screw inside the chamber that holds the chamber to the rest of the carby works loose and restricts movement of the flap
     
  5. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,809
    Location:
    Penna, Hobart
    I agree fully with the above, but I would add there may be a factor of this may be the early symptoms of an ignition switch failure. Badly burned contacts increase in resistance and lower the voltage getting to the coil, especially when the overall system voltage is lowered by cranking to begin with. They are a cheap thing to buy ($20-30), good to have in the tool box regardless, and to get you out of a tight spot takes 30 seconds to remove the plug on the one in the column (bundle of wires together at the bottom of the cowl on the column) and plug directly into the spare, then turn with a screw driver.

    Replacing it permanently is quite a bit more involved, but worth the purchase and trying it for the small initial cost. The worst case is it isn't a factor this time and you have a spare for the time it is.

    Adrian
     
  6. Basil Bus

    Basil Bus New Member

    Messages:
    15
    Location:
    Hobart
    Thanks tintop. I had a chance to take a better look and it seems the butterfly is actually fouling the body of the carby, which prevents it rotating closed. Not sure what I can do about that. I think my main problem is with the starter/leads etc so I'm concentrating on that for the moment.
     
  7. Basil Bus

    Basil Bus New Member

    Messages:
    15
    Location:
    Hobart
    Thanks Barry,

    It's carbs. I've disconnected the domestic battery now. I have had a starting issue for a while now. As I said in my original post, often it would "bog down", as if it was flat, then speed up. It would do this whether it was cold or hot but it didn't happen all the time. I took it to an auto-electrician who could find nothing wrong and said it started perfectly for him.

    At the moment the starter seems to be struggling most of the time even with a battery that is brand new. This morning, warm and dry, I managed to start the bus but the starter struggled at first, then spun rapidly, briefly and then bogged down again. But the engine did fire. Temperature and dampness seem to make a big difference although I've checked inside the dizzie for moisture and have sprayed everything I can think of with WD40.

    I had a starting saga some years ago which frustrated the auto-electrician and turned out to be a problem with the engine locking up and not turning over, rather than an electrical problem. During the course of that he installed a second earth strap from the battery neg and some sort of relay to overcome possible voltage loss from the wiring to the ignition switch (I think - I'm not an expert).

    I've got a bit of time now and will start looking more closely at connections etc.

    I should add that the battery goes flat very quickly now. Even the brand new one.
     
    Last edited: Apr 15, 2019
  8. Basil Bus

    Basil Bus New Member

    Messages:
    15
    Location:
    Hobart
    Hi Adrian,

    Thanks for your thoughts. As I said in my reply to Barry, at the time of another starting issue the auto-electrician "installed a solenoid relay kit to the starter". I gathered that was to overcome voltage loss via wiring to the ignition switch. Do you think that the ignition switch could still be a contributing factor?

    The auto-electrician could not find anything wrong with the starter at the time.

    At times the starter sounds like it's making an enormous effort to turn the engine over and the battery (even the brand new one) goes flat very quickly. That would mean that the system voltage is very low and makes it more likely that the voltage at the coil isn't high enough, I guess? Can I measure voltage at the coil while cranking the starter?
     
    David H likes this.
  9. Luckyphil

    Luckyphil Well-Known Member

    Messages:
    5,960
    Location:
    Gosford
    If the ignition switch or the relay since fitted was faulty then you would not get anything so voltage loss must be elsewhere IMO.
     
  10. 68BUS

    68BUS Well-Known Member

    Messages:
    4,432
    Location:
    Brisbane
    Following this with interest. Apart from the very occasional hot start issue, Evie starts easy first time every time.
    But in Manly she felt like the starter battery was low on juice first time trying then started on the second.
    She was sitting for 3 days prior not driven.
    Then this morning in Canberra she did the same thing.
    But we drove 4 hours the day prior so battery should have been fine.
    I can only assume the cold morning was slowing the mechanical fuel pump or something similar down.
    I believe the cranking battery is healthy. Have 12.4amps after sitting for three days. I appreciate that this would ideally be 12.9amps. But this morning should have been topped up.

    I was hoping to get Col to teach me how to use a electrical meter at busstop but will have to find another guru in his absence as electrics still confuse me. Got the basics to about 70% competency. But need to get my knowledge to intermediate levels.
     
    Dredhead and David H like this.
  11. David H

    David H Well-Known Member

    Messages:
    4,663
    Location:
    newcastle
    Hi Basil Bus,
    Agree with Mordred & the others. It's an earth issue but where is the question. Ignition switch cheap & easy to help isolate the problem.
    So new batteries don't go 'dead' real quick so where is the energy going:rolleyes:. If it was going somewhere you would have heat in wires & lots of it:(. My guess is it's not leaving the battery as it can't get there (earth/starter & it's random with temp/humidity) & that all runs thru ignition switch;). Get thee one:).
    www.justkampers.com.au/search/result/?q=ignition+switch+T2+Bay
    Cheers
     
    Last edited: Apr 15, 2019
  12. Barry

    Barry Well-Known Member

    Messages:
    3,583
    Location:
    Abbotsford NSW
  13. 68BUS

    68BUS Well-Known Member

    Messages:
    4,432
    Location:
    Brisbane
    More the settings on the meter then where to stick the probes.
    12.9 was taken from my ute dual battery box. Lists 12.9 as being full. 12.4 it lists as 60 or 50% full.
     
  14. cbus

    cbus Well-Known Member

    Messages:
    11,700
    Location:
    sunshine coast
    Assuming wet cell lead acid or gel batteries which is likely.
    12.8V full charge rested .
    They charge at 13.8-14-2 input.
    Bit like fluid pressure, you need higher pressure
    ( voltage) on one side to ensure flow.
    When charging you will see charging voltage.
    Rest from high discharge loads or charging for about 1/2 hr before testing to ensure battery is showing actual state of charge and not a surface charge.

    If temperatures are cooler overnight then the extra viscosity of engine oil might be part of the difference in cranking speed if starter is just coping in Qld.

    A good battery should hold 12.6V overnight if no significant loads.

    You may notice a difference between 12.8 and 12.4 V in cranking if things are marginal.

    Multi should have 3 sockets for the cables.
    Centre is common or ground/ earth/ negative.
    Black lead.
    Right hand socket is everything except amps I think.
    ie. It does volts, resistance ( omega sign) , dwell ( points if you have them and it has that function)
    Red lead .

    Dial goes to V 20v scale.DC.
    Should be different symbols to denote DC and AC .
    Google the manual for the model multimeter you have.

    When testing, ensure you have a clean contact.
    Scratch it if necessarily to check.

    If voltage isn't as expected scratch it again and retest .

    For battery testing.
    Test across battery terminals.
    Red lead to positive
    Black to negative.
     
    Last edited: Apr 15, 2019
    68BUS likes this.
  15. cbus

    cbus Well-Known Member

    Messages:
    11,700
    Location:
    sunshine coast
    BasilB.

    Check your timing.
    (Just a long shot)
     
  16. 68BUS

    68BUS Well-Known Member

    Messages:
    4,432
    Location:
    Brisbane
    Thanks Col!
     
  17. 68BUS

    68BUS Well-Known Member

    Messages:
    4,432
    Location:
    Brisbane
    Yes, oil grade could well be the issue. I did not think write of that.
     
  18. cbus

    cbus Well-Known Member

    Messages:
    11,700
    Location:
    sunshine coast
    Does mean starting power is marginal tho as I always ran 20/50 in Melbourne.
    Either power delivery to starter or starter insufficient.
    Guess you have higher compression as well as bigger capacity ?
    Just guessing but wonder if a high torque starter is used on these engines ?
     
  19. 68BUS

    68BUS Well-Known Member

    Messages:
    4,432
    Location:
    Brisbane
    Would be the same starter i had on it when running the 1776.

    Started well this morning. I pumped the throttle twice before turning key. Not sure if that would have helped.
     
  20. cbus

    cbus Well-Known Member

    Messages:
    11,700
    Location:
    sunshine coast
    Quite possible.
    Slightly different technique and a bit more juice for cold starts makes sense.
     

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