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Problems with engine cut out, engine not starting, fuel pump, starter motor, solenoid

Discussion in 'Fuel System & Electrics' started by bucephalus, Jan 26, 2013.

  1. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    Hi Folks,

    Of late some intermittent nagging problems with the kombi have developed into serious pains in the ass. They may or may not be interrelated but they need to be sorted out. Specs : 1976 Kombi, 2L motor, mechanical fuel pump. This may turn into War and Peace... here goes :


    1) Driving along and for no reason engine cuts out without any warning. It has happened when motor was hot after 100kms and it has happened driving up the street with the motor quite cool. So far I have been able to restart the kombi while it is coming to rolling stop. Other times I have had to wait a little while.

    Reason still unknown but I have since checked and cleaned all the battery terminals, connections, wiring, replaced the coil, cleaned the inside of the distributor (electric, not points) and leads to the plugs. I have not had the problem since but I haven't done much driving distance either... confidence level problem fixed... low.


    2) Similar to (1)... Driving along but engine begins to feel like its starving for fuel, jerky, and after about 100m engine cuts out and rolls to a stop. Will not restart until after about 1.5 hours. Last time it happened was really bad and did not restart at all. Had to get towed back to nearest town (Mt Surprise) and spent the afternoon with friends there working on it. Had the mechanical fuel pump off. Called mechanic in Darwin who had worked on it and he said it sounded like the fuel pump push rod. I was advised that over time it will wear down and to try extending it by welding one end to build it up. This we did as one of my friends is a very good welder. We lengthened it by about 1.8mm. We ground and smoothed it off nice and tidy and refitted it. I did take measurements but naturally do you think I can find the paper I wrote on, nope. Does anyone know what the length of a brand new fuel pump push rod? I want to buy one.

    Since then I have not had this particular fuel starving problem... only the immediate cut out one (1).


    3) Possible vapour lock. Haven't had this for a while but I still think its lurking in the background. Generally occurs when motor is hot and I do alot of stopping and starting around town. Eventually after taking off I might get 50m and then it will starve, jerk a bit and come to a rolling stop. Have to wait about 1.5 hours before kombi will restart.

    Suspect that only an electric fuel pump might save me here. Possible that lengthening the fuel pump push rod has helped.


    4) Engine will not start. This is usually after driving around a bit, stopping & starting a few times, just regular driving around town. Sooner or later it will not start at all. The starter motor fires up but it seems that I am not getting a spark to the plugs. Using a voltmeter we found that we were not getting charge to the coil??? Bizarre! This was around the same time as (1) and prompted my cleaning of the batteries, terminals, connections, etc.

    I thought I might have fixed it but today it occurred again. It wouldn't start... and this leads into (5)


    (5) The starter motor and solenoid. Lately there have been some unnerving 'click-click-click' noises coming from that area when I try to start the kombi. This usually results in things suddenly going completely dead. I get under the kombi and gently tap both the starter motor and solenoid. My mate said today that it sounds like the (can't recall the name of it) inside the solenoid is stuffed and I'll need a new one. Normally the gentle tapping fixes things as it did today and it got me moving again, but confidence level is low and I think something will need replacing. Ideas about whats involved here?

    There is an awful lot of dirt and dried mud around this area. I believe that it has a relay in place as well. I intend tomorrow getting under there and cleaning the whole thing up in case it is a case of bad connections, etc. But I think its more then that.


    (6) Indecision/hesitation/nervousness about replacing Mechanical Fuel Pump with Electric Fuel Pump.

    I suspect that the mechanical fuel pump might be on its way out... hard to tell. Why do I suspect it… because of the fuel starving anf vapour lock problems. I have read all the topics about this particular subject and to be honest I have found it overwhelming and only heightened my nervousness about going electric. There seems to be all sorts of suggestions, recommendations, configurations and variations with hooking one up. I seem to require : the electric fuel pump < 4.5psi, an LPG cut off, regulator, and possibly other things that I can’t think of at the moment (an EFI relay hooked to the coil... WTF?!) There was talk of wiring it into the coil, the alternator, and other places... had me baffled. Sounds all a little complicated with potential for problems. I work on the KISS principle. The more (not always moving) parts involved the higher the chance for things to go wrong.

    I couldn't make heads or tails of it all. Talk about having to prime it before starting (how does that work? Just turn key to pre-ignition position for 5 secs before start?), pumping fuel while motor not running (high risk because of above problems), too much pressure into the carby (oh, yes, I have a single carby... long story) and other things. BTW, how to I test current pumping pressure and what the carby requires?

    Please, please, please, can someone provide a clear, simple, decent sized diagram of how this can all be fitted and wired in. If people recommend various configurations (from a simple basic installation to the more complicated), a corresponding diagram would be magic! Its the old 'picture is worth a thousand words' thing. It has to be really simple and clear so that I, a complete dumbass, can understand it. :) Don't be shy about putting in part numbers/brands of things, etc. I couldn't find one though I suspect there must be a diagram already as this is an obvious thing that would be super handy due to how popular this topic of fuel pumps seems to be.


    (7) I think the ignition is wired incorrectly. I have four key positions (which I assume is normal). They currently do the following :

    Position (A) : Nothing, no power to engine or accessories, OFF
    Position (B) : Nothing, no power to engine or accessories, OFF
    Position (C) : What I call "pre-ignition". Accessories are on, coil is getting power.
    Position (D) : Start the engine!

    What I think it should be is this :

    Position (A) : Nothing, no power to engine or accessories, OFF
    Position (B) : Accessories are on.
    Position (C) : What I call "pre-ignition". Accessories are on, coil is getting power.
    Position (D) : Start the engine!

    The difference is Position (B). I'm parked up and want to play the stereo. Currently I put it into Position (C)... I did this the other day and discovered the coil was very very hot. I don't think that should happen. So I think I need to do some re-wiring... correct?



    And there you have it. My little collection of kombi problems. Its all that I can think of at the moment and I hope that I have described them well enough. So, any advice or ideas on any of them?

    Many thanks and apologies for the length of the post. I would have posted them separately but I think they might be interrelated to some degree.

    Doug...
     
  2. splitbus

    splitbus Well-Known Member

    Messages:
    3,313
    Location:
    Brisbane
    What's your fuel line like between tank and pump, pump could be sucking it closed, just a thought
     
  3. oldman

    oldman Super Moderator Staff Member

    Messages:
    8,696
    Location:
    Avalon Beach NSW
    Smokes Doug, that's a list & a half !! Sounds like you have a bit to work through.....
    Electric vs mech. fuel pump.
    Personally I'd keep it stock for all the reasons you've mentioned. last thing I'd need is to fiddle around with fuel line pressure/electrics etc.
    Lots of folk swear by 'em, but I'm not one of them. KISS has worked for my '76 2 ltr &(hopefully) will continue to do so.
    Engine dying/lack of power
    Have you changed out the HT leads? If the old ones are copper cored, over time the copper breaks down & strands break. Once the copper heats up ( when running) resistance builds to the point that the current does not flow efficiently.
    This happened to me a couple of years ago - new leads=no more problems in that instance. Carbon core leads can fracture as well.
    Ignition wiring
    mmm my electrical experience is average, however my stereo is wired up directly to the fuse box - power lead has an in-line fuse. This way there is no need to turn ignition on at all. Not really the answer you're after but it may help prevent the overheating coil.
    I'm not sure that my '76 has an accessories point on the ignition......I'll check when it's light.
    Starter clicking.
    Sounds like the contact point that is normally made when the solenoid throws the contacter (internally) could be carboned up. try replacing just the solenoid - you can leave the starter in position for that.
    If you're really keen you can pull down the solenoid & clean it up yourself.

    Good luck with it all.....you'll get there eventually - just deal with one thing at a time, resolve it & move on.
    Cheers,
    mark
     
  4. syncro

    syncro Well-Known Member

    Messages:
    9,429
    Location:
    Southern Highlands
    I have never ever seen or heard of that in 40 years of VW ownership. It is usually the connectors that fail as copper lasts for millions of years.

    There is no accessories position on the ignition switch.
     
  5. oldman

    oldman Super Moderator Staff Member

    Messages:
    8,696
    Location:
    Avalon Beach NSW
    Phill, it was the last thing I considered too.....don't rule it out just 'cause it hasn't happened to you.
    First time it happened to me was on a Commondore.......last time was on my son's lowy a couple of years ago.
    Gotta consider all options when an answer escapes normal diagnosis..
    Cheers,
    Mark
     
  6. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    @Mike : The fuel line between the tank and pump should be fine. I replaced them about a year ago. When problems do occur I usually stick my head under and have a look and the fuel filter always seems to be full of fuel.

    @Mark : So the solenoid, is this something that can be tackled by myself? Do I just remove it out and take it apart? Are there any tricks to it or is it something that is very risky and I'm likely to balls it up? The carboning up of the contacter... is this something thats easily accessible inside the solenoid? Is it just a case of wiping this contacter and putting it back together?

    If I want to replace the solenoid, is there a particular make/model/type that I require for a kombi? Or are all solenoids created the same and universal?


    Engine dying : I can look at replacing the leads... by HT leads I'm guessing that you mean those thick leads that go from the dizzy to the spark plugs and the one that goes to the coil. Correct?

    Fuel Pump : I would like to keep the mechanical pump as it was made and designed for the kombi. I would like to try getting a new fuel pump push rod. Perhaps Mick Motors or one of the other suppliers might have one.
     
  7. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    And yes, it is quite a little collection of problems but I still feel that the answer has to be a simple one.
    This thing with power not getting to the coil. It baffles me. It doesn't happen all the time and usually only after a little bit of driving around.
    Normally if I turn the key to pre-ignition, power should flow to the coil. From memory when I test the coil I get a reading of around 9-10 volts. When the motor is running this drops down to 5-6 volts. (Is that normal?) When the problem occurs I get 0.

    So I figure that the problem has to be between the batteries and the coil. I cleaned all (or at least all that I could figure out) the terminals, connections, etc thinking that perhaps a dodgy connection somewhere was causing the problem. Am I right in thinking that it has to be between the battery and the coil? Is there anything else in that loop that I should check?
     
  8. syncro

    syncro Well-Known Member

    Messages:
    9,429
    Location:
    Southern Highlands
    Commodores have carbon leads. This is a common problem with carbon leads.
     
  9. syncro

    syncro Well-Known Member

    Messages:
    9,429
    Location:
    Southern Highlands
    I would be looking at the ignition switch.
     
  10. cbus

    cbus Well-Known Member

    Messages:
    11,932
    Location:
    sunshine coast
    Only a couple of things.
    Ign switch seems a probable suspect. power to coil goes thru it ,obviously.

    The coil getting hot when on 'accessories' meant the switch was on 'run' position.

    A long shot poss. Does the electronic unit you have in dissy have any components that require a heat sink paste to ensure good thermal contact. This was a classic prob with some eletronic systems on other vehicles. gave symptoms like fuel prob. when cool were ok.

    low power to starter solenoid causes the clicking.
    If all connections clean and tight from batt to starter then the contacts inside starter solenoid can be checked. cheap to buy.
    Added relay from key to starter solenoid may be faulty. change it if you think that may be a prob.
    key and any associated switch could also be an issue again
     
  11. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    Interesting. Never actually thought about checking the key ignition switch as its such a small thing... its just a small cylinder thing, right? Am I just checking for loose wires or something?
    So, to state the completely obvious, power goes via ignition switch to coil, not direct from battery to coil.

    Unclear what you mean by : "Does the electronic unit you have in dissy have any components that require a heat sink paste to ensure good thermal contact." Heat Sink Paste? Where does that actually go?

    "low power to starter solenoid causes the clicking. " : this can be checked just using voltmeter? What sort of voltage would be considered normal... full 12 volts?
    Again, a solenoid, is that just a standard thing or do I need a specific model. Like the coil, there are quite a few different ones and you need to get the right one. Same for solenoid?
     
  12. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    "low power to starter solenoid causes the clicking. " : Lets say that the batteries (I have two that go through a big black isolator dial) have full charge (+12volt)... what possibilities might cause low power to get to the starter? Bad contacts, poor old wires, resistance somewhere?
     
  13. Red Kev

    Red Kev Member

    Messages:
    468
    Location:
    Moonee Beach
    Hi Doug, I once had problems similar to (1) and (2) and it was a devil to get to the bottom of. It was the fuel pump push rod. I doubt you've done it any favours with your mate's welding, regardless of his skill. Replace the whole pump or, better, get an electric one. Yeah, yeah, mechanical ones are nice and stock and all that, but so's a horse-and-buggy. Move on ... ;) I added an electric fuel pump to my 1600-based engine, easy: tank --> fuel pump --> carbs/injectors --> regulator --> fuel return to tank. Not sure how it would fit to a type 4, but I can't think it's that different. Yes, a good quality pump and regulator will cost some ... Yep, 'priming' is a matter of letting the pump get a head start when your turn the key, from On to Ignition. Five seconds, no biggy ...
     
  14. cbus

    cbus Well-Known Member

    Messages:
    11,932
    Location:
    sunshine coast
    Being careful and ensuring k is out of gear.
    run a wire from battery to the contact on the starter solenoid where the ign wire connects. its the small wire with a push on spade connection.
    If the starter kicks in strongly and will start when the ign key is on run posn when you do this then the contacts in the solenoid are probably ok. even if a bit worn.

    with a multimeter , earth the black probe on a clean part of starter body. red probe into wire from ign switch [with it dissconnected from starter. ] Attempt start of kombi with key. you should reach at least 12v if battery is over 12.5v.

    If its much lower you have a resistance somewhere. probably the ign tumbler as it seems to have other issues as well.

    Often people try to overcome this with the addition of a cheap relay to supply more power to the starter solenoid during start .
    this is often placed on the back wall of engine bay. a small black relay with a few wires off it. if you follow the starter wire you will find it either comes from the front[ign ] or from a solenoid in engine bay which will have the ign wire from front attached to it. relay will also have a wire from a power source such as the battery.
     
    Mordred likes this.
  15. syncro

    syncro Well-Known Member

    Messages:
    9,429
    Location:
    Southern Highlands
    Why is there a starter relay?

    This is normally because the ignition switch is faulty.

    The ignition switch is made of two parts, the key tumbler and the electrical switch. The electrical switch is just a plastic housing with contacts which can overheat when owners put high wattage headlight globes in or high power stereos etc. The plastic housing also cracks with age or when owners have heavy keys.
     
  16. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    @ Red Kev : "tank --> fuel pump --> carbs/injectors --> regulator --> fuel return to tank". Wouldn't it be "fuel pump --> regulator --> carbs"?

    Not sure how this "fuel return to tank" bit works. A new concept for me. :)

    Priming electric fuel pump... cool, I understand now. Thanks. :)

    I'll do some testing on the starter/solenoid/ignition this afternoon... this is all new for new. Bit worried about zapping myself or blowing something up. :)
     
  17. bucephalus

    bucephalus New Member

    Messages:
    56
    Location:
    Cremorne, Sydney
    OK, just gone out and my kombi is playing possum... its dead. This is a good starting point as its exhibiting the problem. This is what I've got :

    1) Both batteries showing with 12.59 volts.
    2) With key at position C :
    - dashboard lights are on (ie. oil and battery lights)
    - coil testing at 0 volts, ie. no charge.
    3) Turn key to position D, ie. start.
    - dashboard lights still on
    - nothing happening with starter motor, no action at all... dead.

    At this time I haven't tapped the solenoid.

    Just so I'm on the same terminology, with the key positions, when I refer to Position "C" as "pre-ignition", is that also what others refer to as "run"?

    Stay tuned... :)
     
  18. kombivan

    kombivan New Member

    Messages:
    853
    Location:
    Forster
    so many conversations
    1 engine misfiring and cutting out there is a solenoid screwed into the side of the carby this closes when the ignition is switched off turning the engine off your problem is you have shit in your fuel tanl probably rust particles just unscrew solenoid and there is a very fine hole inside just get a wire brush and cut one peice of wire off and use it to clean the jet in the carby solenoid then replace it. this will keep annoying you untill you flush the fuel tank and it pays to run full rather than empty for it to rust.
    2 starter motor needs rebuilding or a new recon one you can get from the states for about $150.00 delivered to your door from bnrparts on ebay.
    3 coil always gets hot when you turn ignition on for raido etc bad thing to do you will blow your coil up doing that.
    position a on key could be accessories or it could be for steering lock or it could be for ignition key removal and the same could be said about position b but I haven't had a bay window for 17 years I got a T3. hope this helps you.
     
  19. kombivan

    kombivan New Member

    Messages:
    853
    Location:
    Forster
    the solenoid on the side of the carb looks like a very small aluminium can screwed into it
     
  20. kombivan

    kombivan New Member

    Messages:
    853
    Location:
    Forster
    and has a wire connected to it.
     

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