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Electric Fuel Pump?

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

  1. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,338
    Location:
    Melbourne Bend of Islands
    After rejecting the mechanical pump I fitted an electric fuel pump I found in the shed. It works and Schmetterling motors well but:

    Its a tempory mounting and I will revisit and mount the pump underneath and out of sight (one day) if it is the best fix.

    Question 1. Should I pull the mechanical pump and remove the push rod OR remove the pump and plate over?

    Question 2. Should the electric pump be higher or lower than the tank/ carbs?

    Question 3. Should there be a safety cut-out on the pump and how is it done?
     
  2. T1 Terry

    T1 Terry Active Member

    Messages:
    1,309
    Location:
    Lake Illawarra NSW
    Hi Alpal,
    In my oppinion an electric solidstate pump is the ultimate answer to kombi fuel starvation problems.

    (1) I removed our mechanical pump and plated the hole to reduce the oil leaks by at least a couple along with the pushrod.

    (2) This depends on what type of pump you have but it would need to be mounted very high to be above the fuel level of a full tank.

    (3) There are a number of methods for doing this but the easiest is to use an LPG safety switch and a relay. The Safety switch has 3 terminals and an earth wire. One terminal goes to the + side of the coil, one terminal to the points side of the coil and the last marked "gas valves" goes to 86 on the relay. 85 on the relay goes to earth, 30 on the relay goes to the battery + and 87 on the relay goes to the + on the fuel pump.
    The relay is to reduce the load on both the safety switch and the ignition circuit.

    The safety switch has a 5 sec priming curcuit so the pump will run for 5 secs after you turn the ignition switch on and then stop till it sees a set number of pulses from the coil. There are so many different ones I can't tell you how the other 2 terminals are marked but they will come with a wiring diagram.

    You can buy the safety switch for an LPG fitting station, the relay from an auto parts store or auto elect, a switched on supplier or auto sparkie will also have a prewired plug for the relay with a fuse in the battery supply line but it's not a huge job to just wire it up yourself and best to fit an inline fuse to the battery.

    Hope this helps

    T1 Terry
     
  3. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Thanks for that info - I'm in a similar boat... Rebuilt motor came back to me with the original pump and a recommendation to fit an electric unit. One more thing to sort out before reinstallation!
     
  4. ttmck

    ttmck Super Moderator Staff Member

    Messages:
    2,733
    Location:
    Hallett Cove STH AUS
    Good work terry , ive have mentioned this set up in previous posts lpg solenoids are cheep and very effective in stopping fuel entering the engine esp when parked on slopes
    very nasty when the engine fills up with fuel

    Rubber mount the fuel pump to reduce noise , also replace hoses with correct diameter

    universal diagram for wiring accesories using a relay

    [​IMG]

    relays have numbers underneath
    [​IMG]

    internal windings of a relay circuit diagram
    [​IMG]
     
    Last edited: Sep 2, 2009
  5. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,338
    Location:
    Melbourne Bend of Islands
    Thanks guys. All taken on board.
     
  6. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Al did you end up installing the above solution? How did it all come together for you? I'm heading out to get some of the bits and pieces today and hope to install something similar in the next few days...
     
  7. Alpal

    Alpal Moderator Staff Member

    Messages:
    8,338
    Location:
    Melbourne Bend of Islands
    Been slack and have not got back to car.
    Did a lot of K's travelling to the Pyranees, Little desert, then back to the coast and up and down the Great Ocean Rd and the electric fuel pump worked a treat.
     
  8. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Sounds like fun and great to hear the new set up works well.

    What was the max psi rating of the pump that you used? There are a few on ebay with 3.5, 4.5psi ratings - I'm not sure how big the difference really is. A few other posts on the subject suggest 3psi as adequate, but one of the pumps at that psi is advertised as being for "small Japanese car" which doesn't inspire confidence. Do the cheaper Chinese units do the same job? At 40-50$ they look like better buying than the other brands and particularly a US model at Repco for the bargain price of $200+ or even the Facet pump at about $90 at Burson's.

    With no return hose to the tank, how do the electric pumps cope with over-supply?

    The relay is available by Narva at Repco stores (as I discovered this morning doing the rounds of the parts suppliers and doing some research) - with the terminal layout as described above by Tom. However their catalogue lists the relay with amp ratings of 30 and 40, each with a choice between resistors or diodes - so in the same terminal format you're looking at a choice of four different types, again there isn't enough information at my disposal to recommend any of them over the others, or even if it really matters.

    If anyone could start throwing around actual part numbers it would be fantastic, even if only to save me from demonstrating my ignorance to parts counter staff everywhere I go!
     
  9. Leigh77

    Leigh77 Member

    Messages:
    350
    Location:
    Granton Tas
    I have just had a new elec pump put in in the last couple weeks, think its the same as the facet pump Nikferatu mentiond above, very good pump, runs at approx 4psi, plenty pressure as the 2lt motor only requires about 3.5psi, this is currently wired direst to the coil so as to get it workin, but i have a oil pressure swith that is coming sometime soon which will operate the pump, my mech tells me that wiring it to the oil pressure swith, should you have the unfortunate luck of rolling the bus then the oil pressure swich will shut of the pump thus stopping fuel from pouring out over your hot engine, wiring it to the coil will allow the fuel to keep pumping till the ignition is turned off... once i can get somne more details as to part number etc of the oil pressure swith i'll post it up, hope thats some food for thought... :D but the facet pump is worth the look at least, i could post a pic sometime tomorra to show where its mounted... :D

    Leigh
     
  10. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Thanks Leigh, would love to hear more about it - there are a few options out there for safe installation, I'm not sure which is best ATM but the oil-pressure avenue sounds reasonable. I'm keen to get my hands on an LPG cutoff solenoid as well but again no idea on price or correct type - none of the LPG places I turned up on the net seemed to be answering their phones today!
     
  11. Leigh77

    Leigh77 Member

    Messages:
    350
    Location:
    Granton Tas
    No worries, as soon as i find out some details etc on the oil swith, i'll let you know, but the facet pump is worth while i think, little bit noisy when the engine aint running (thats when the ignition is on but not the engine running), but ya cant hear it over the engine anyway, lol, or the boom box, lol, :p

    Leigh
     
  12. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Had a mission getting the old pump off, rebuilder didn't bother replacing the socket head cap screws that were holding it on and were totally flogged out. Ended up putting a drill through the pump body flange between the bolt heads and the block to disintegrate the thing enough to get it off and the old bolts out. Then install the blanking plate with some new bolts and a bit of bluemax. Hopefully that should do the trick!

    [​IMG]

    [​IMG]
     
  13. Bricktop

    Bricktop New Member

    Messages:
    181
    Location:
    Whitsundays
    Where did you get the blanking plate mate?
     
  14. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Bob at Volkscare in Adelaide, phone 08 83691233. It was about $22 including gasket and postage to Brisbane. Thanks 1500king for the tip-off! :)
     
  15. Bricktop

    Bricktop New Member

    Messages:
    181
    Location:
    Whitsundays
    sounds good, i noticed something similar for the same price on Classic Vee Dubs site, and wondered if that was the part.
     
  16. Dingostrategy

    Dingostrategy Active Member

    Messages:
    4,322
    Location:
    SW Vic ++
    Worth mentioning in this thread, I think, that in fact some carbs prefer a much lower PSI. My Kadrons for example are recommended by lowbugget to have a 2psi rating. You can get a pressure regulator. Of course, i learned this after installing a 5 psi inline pump (no cutoff)! It tends to starve under high revs which I believe is a symptom of the high pressure situation. the regulator is $50 or so and seems simple enough to install. The job is on the list.
     
  17. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    I'm pretty keen to avoid that - thanks for that info. Seems like the pump will either build up pressure in the fuel line or just jam too much fuel into the carburettor if the psi is too high... Sounds like the bottom-range pump will do for starters. I know the feeling of buying the wrong parts and only finding out later, I'm keeping the questions coming to hopefully avoid anything like that happening to me again! Where do you get the regulator from?

    Thanks again for the input. :)
     
  18. Leigh77

    Leigh77 Member

    Messages:
    350
    Location:
    Granton Tas
    Here is the fuel pump i put in, and its position, hope this helps. :)

    [​IMG]
    [​IMG]
    [​IMG]
     
  19. Necro

    Necro Active Member

    Messages:
    2,623
    Location:
    Victoria
    After having to drain a engine full of petrol three times in two months, I now have an lpg cut off safety switch...yay...some newer pumps have them but the ones from a couple of years ago don't. They don't cost much but save alot of hassle, I would recommend them with any electric fuel pump as a precaution...
     
  20. nikferatu

    nikferatu Active Member

    Messages:
    1,457
    Location:
    Bracken Ridge, Brisbane
    Thanks for all the info guys. That's about where I was thinking of putting mine, Norco. Now just have to find somewhere to buy the lpg safety switch...
     

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