Electric Fuel Pump?

Discussion in 'Fuel System & Electrics' started by Alpal, Aug 31, 2009.

  1. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    I'm no mechanic either ;)

    But hope some pointers help in finding correct answers.
    Always learning from those I believe and thru revelations or mistakes .:rolleyes:

    Original engine at that age is good.

    Yep. Red pin on threads viewed in each section indicates 'sticky'.

    Good luck on rebuild.
    Upgrading a bit?

    Cheers
     
    Ninga likes this.
  2. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,250
    Location:
    Melbourne Bend of Islands
    My assessment from looking at 1800 block again. Sleeve tube fitted to block for push rod to slide in does not have an oil hole. Case at both end of push rod has gallery area that is drained back to sump. Possibly pressure fed oil to camshaft would 'bleed' into galleries to splash push rod. Not sure where oil level is relative to push rod ends.
    Do not believe leaving rod out will cause any problem.
     
  3. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,635
    Location:
    Penna, Hobart
    I think if we find that the hole is in some cases, then fitting the rod as modified in the pic would a) block the flow the right amount b) not cause issues with the cam as it has been shortened and restricted in movement by nut welded on. If the block has no gallery hole, rod in or out shouldn't matter.

    I have also been lead to believe the original fuel pumps were made not to let fuel into the crankcase but out the drain at the bottom of the pump in the event of a diaphram failure as the pressure in the crankcase is higher they fail. You often see some oil leaking from them in older pumps. Never heard of a pump fault causing dilution but I have heard a lot of cases of needle valves failing and causing sumps full of fuel. This happens in every case I have heard once the pump has been replaced with an electric one, in most cases by parking nose up on a hill or sometimes with a pump that is rated higher than 5 psi. The old pumps have a valve that stops the flow when not running.

    As much as I hate another point of failure, a solenoid valve in the fuel line as close to the tank but after the filter as practical, and wired in to the same tachometric relay controlled fuel pump feed is a good solution.

    Adrian
     
    David H likes this.
  4. Tash

    Tash Member

    Messages:
    68
    Location:
    Kalgoorlie
    Greetings all - I'm the one that via facebook has rekindled this discussion. Not through any knowledge of my own, but a lack of knowledge (and wish to learn) about my bus and changing to an electric pump. Sad to say, I have recently found petrol in the oil, even in the oil breather hose. I haven't driven since then . . . the last two weeks I've been collecting parts - I have a facet pump, a tachometric relay, a cut off solenoid, new oil and filter and a whole pile of rags and plenty of crc!

    I've removed the old pump (still hoping this was the reason why fuel went the wrong places), but am unable to remove the push rod. A friend who is far more competent than I am with a grinder is coming around tomorrow morning to trim the push rod so I can fit a block off plate. I'm sure I'll be back with questions soon, please bear with me :)
     
    David H likes this.
  5. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,250
    Location:
    Melbourne Bend of Islands
    If the car was parked on a slope would also be looking at float valve in carbi.
     
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  6. oldman

    oldman Super Moderator Staff Member

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    7,776
    Location:
    Avalon Beach NSW
    ....would also suggest that you are more likely to get appropriate info./advice here, than on facebook.
    There are members here with proven credibility, happy to assist....
    Cheers,
    Mark
     
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  7. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Bl**dy glad I've got a fuel injected with electric pump but as always on KC there is something to be learnt:). Bought a 'cut off valve' (thanks Tash & others to make old boy bullet proof) (b thing came with NO instructions) & would appreciate some knowledge of best place to fit. It's got 8 mm barbs on it (can deal with that) & one male power connection. I guess the male goes to 'key activated' & opens it & above suggests install past the fuel filter.

    It's me just being sure as tomorrow is St Patrick's day. To be sure...to be sure;)!

    P1110211.jpg2.jpg


    Am I on the right track:confused:?
    Cheers
     
    Last edited: Mar 16, 2018
  8. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    Have you got a tachometric relay as well ?
    You need that to run the solenoid valve to ensure valve closes if engine stalls in accident or fire and ign is still on.
     
  9. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Wouldn't know one if I tripped over it cbus;). Just know it's F/I. Would that have one controlling it?
    So where in the electrics would that go? Coil? Tachometric relay ( I guess by description these pick up on 'pulse' & thus no pulse shut down the solenoid??) needed in line for power to solenoid?
    Doesn't care where key is. I think I'm getting it:( slowly.
    Cheers
     
    Last edited: Mar 16, 2018
  10. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    Actually . think the double relay that runs pump on efi may be a tachometric ??
    Someone should know.
    I'll check.
     
  11. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Thanks
     
  12. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
  13. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Damn I wish I was half able to understand some of that;).
    I've bypassed these relays in time past. In carb models the relays just do the 7v versus 12v start transfer. Didn't see the totally different significance for F/I.

    Best I could say I have some sense of what's being said.
    So pump shuts down when spark stops? Regardless of key position? Not so sure of this cbus given the 94 fire. With "tachometric like"??
    So that solenoid is not neededo_O? or at least easily wired:D.
    If F/I has that 'shutdown' capacity I'm thinking just in 'fuel line off ignition' for solenoid??
    Stops fuel & ensures nothing more than the current system has? Just spent $50 that may not change anything??
    Your thoughts as always appreciated.
    Cheers
     
    Last edited: Mar 16, 2018
  14. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    Considerations...
    Doubt if pump will restrict flow if stopped.
    You don't have a siphon prob potential into cylinders due to injectors being closed.
    A damaged fuel line could still siphon fuel. Probable?
    Pump power supply / shutoff is via AFM switch closing due to no airflow once engine stops.

    Therefore my take is run the tachometric relay from coil as in a carb setup and use that to control fuel shutoff solenoid.
    Saves a complication finding another source of power.

    Prefer a non barbed fittings and a loop in fuel line to allow bypass if relay or solenoid fails.
    Have had that within hours of fitting on new products.

    https://www.whitworths.com.au/brass-hose-tail-1-4-npt-to-10mm
    Example of shape only.

    Hope it helps.
    Cheers
    Col
     
    Last edited: Mar 17, 2018
  15. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Thanks cbus.
    See you soon at Bus Stop.
    Cheers
     
  16. David H

    David H Well-Known Member

    Messages:
    2,910
    Location:
    newcastle
    Diaphragm should unless ruptured. Always the potential tho.
    New fuel lines:D.
    Is it just an extra fault point in an F/I as @Alpal says?
    The odds of engine fire with no ability to turn key off is 'very low';) (unless my heads thru the windscreen & then I may not care:D). Understand the tachometric stuff & thanks. If I fit this solenoid (via tachometric relay) I understand the moment the engine (spark) stops the fuel shuts off? Have I got it?
    Cheers
     
  17. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    odds of delay or not turning key off in accident is high.
    Chances of delayed awareness to fire, high under normal circumstances.
    Blazecut said to be loud when it goes off ?
    Blazecut should also kill engine due to lack of O2.
    Odds of fire in well and correctly maintained kombi, low.

    By higher risk factor I mean fire melts plastics etc to establish a better hold against being extinguished or means vehicle is unserviceable due to exposed wiring at least.

    My take anyway.
     
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  18. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,635
    Location:
    Penna, Hobart
    No hole at all. The original mechanical pumps were well made and seem to have been designed to avoid leaking into the sump. But I think you will find most electric ones do not have a non flow type valve, especially the rattle ones,

    I agree with a cbus that it would be good to have a simple bypass system for the solenoid too, as I have had issues with failures at inopportune moments, but that can also go for pumps and the relays too. Where do you stop trying to make everything redundant?

    The Peel CP30 tachometric relay has a 12 amp rated contact which should run the solenoid and the pump, but I would fit a standard relay controlled by it to reduce the load, as the start current of pump and solenoid can peak quite a bit higher.

    There really is no perfect solution but if you can make the components easy to get to in case of failure and carry a few basic spares or bypass options you might be getting close to the mostly reliable original.


    Adrian
     
  19. Mordred

    Mordred Super Moderator Staff Member

    Messages:
    2,635
    Location:
    Penna, Hobart
    If you can put the tachometric relay near the engine, you have a much better chance of shutting the solenoid off. It has a delay of a few seconds when you turn the key to prime the pump before starting to check for pulses.

    As cbus said melted contacts or shorted cables after damage in an accident, or just sheer panic when you see smoke are likely reasons for the ignition not to shut off that people don’t think about.

    Adrian
     
  20. cbus

    cbus Well-Known Member

    Messages:
    10,666
    Location:
    sunshine coast
    Agree with Al and Adrian re multiple redundancies.
    Where do you stop and is it creating another potential fail point


    Bypassing with hose is easy.
    Easier if designed into installation and acessible while on roadside.
    Hence the easy pull off fitting and ensure quality clamps with screw or clamp tabs acessible.

    Bypassing relays easy with a jumper wire of suitable sizing. I carry a couple with connections fitted. Some spare variations of connectors always in box somewhere.
    If one got anal a fuse could be be included in jumper but that would take the fun out of fault finding :)

    Jumper also handy for hotwiring to coil or remote operation of starter.

    While searching recently came across a demonstration of pump giving insuffient pressure for starting while cranking due to low battery V.
    V indicated would have been borderline for coil operation as well? 8 V under load.

    Another showed cylinder pumps being variously vane or turbine type operation . Haven't opened a vw one but assume similar.?

    Facet pumps certainly don't have ability to block fuel when off but the vane / round type have a back valve to maintain line pressure for rapid starting.
    Crap in these may be a cause of pressure bleed and hard starting requiring some cranking to build pressure.

    A bypass for stuffed pump on carbs can be an elevated container plumbed to carbs.
    Some caution needed due to being a dodgy setup with fuel inside vehicle :eek::rolleyes:
    Politically correct warning...
    May constitute " a little bit of knowledge can be a dangerous thing" and be a precursor for entry to Darwin awards. ie I disavow any responsibility if you try it.
    May not give full pressure for hwy speeds ;) ??

    Efi? Bad luck . normal operating pressure around 30psi.
    Maybe the window washer trick as shown on "Bush mechanics" :eek:

    Although a spare pump would be realistic for remote driving if running efi.
     
    Last edited: Mar 17, 2018
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