Engine will not start after rebuild - suspect electrickery.

Discussion in 'Mech Tech' started by rickyrooo1, May 11, 2014.

  1. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    Hi chaps and chappesses, as some know the van has just had engine rebuild all went well it's in and turns over nice- no build issues, however it won't start and we've trouble shot as far as we can and are stuck......
    we have spark
    coil is good and powering
    turn the key you can hear the left side double relay click
    the fuel pump is not running ignition on or under cranking (hence no start obviously)
    put a bypass 12v from battery to pump makes pump run but didn't risk starting as what's the point - it just proved the pump hadn't failed.

    suspect relay isn't opening a feed to pump but unsure if bypassing the pump would be a good plan as the relay (we presume) opens something else, we ran out of time so bus abandonned again.

    anyone got any clues as was wanting to go away for my birthday next weekend :(
     
  2. I have a feeling, will need to check, on FI the pump doesn't run all the time anyway
     
  3. Sorry to hear this Ricky :( Glad it all went back together OK though.

    There is a good explanation of the double relay here - perhaps that can be some help:

    http://www.ratwell.com/technical/DoubleRelay.html

    My initial thought - are the FI wiring harness earth connections still connected? - underneath the air plenum...
     
  4. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    no but it needs to run to start, don't forget i've had all fuel lines off and replaced them so there is no fuel in the system
     
  5. Fuel pump should only start pumping when you start turning the engine - it kicks in when the flap in the airflow meter is moved by air being sucked in by the engine. You can test it by turning ignitiion on and then manually pushing the flap open in the airflow sensor (with the air filter off!)
     
    zed likes this.
  6. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    i remember seeing them, there's no reason they came undone we never pulled them
     
  7. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    zed has been under the van while i cranked the pump does not run, yet put a wire off the battery to the pump to bypass it and it does run hence we know it's something not letting it run
     
  8. Have you checked the wire from the relay to the pump for continuity?
     
  9. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    if anyone who knows a bit more than me can help i will pay your time and travel, zed is as stumped as me to be honest, i'm rubbish at electrical troubleshooting and zed knows little about f.i vans - if you can help anyone please let me know.
     
  10. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    we ran out of time mate it became clear by 6pm we were not gonna get finished - zed had a 2 hour drive so we had to give up
     
    moley76 likes this.
  11. I am sure James @Greenwesty knew abit about them?
     
  12. I think @pkrboo is our best FI expert here so hopefully he will have some idea for you.

    My guess is double relay area.
     
  13. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    mine too, obviously we disturbed all wires and unplugged things to drop engine, a few years ago it did this on a weekly basis and i used to waggle the relay wires and it would start..... i even said to zed when i unplugged it - this is gonna cause a problem......
     
  14. davidoft

    davidoft Sponsor

    When ya going back ? , did you have everything connected electric wise?
     
  15. If @Greenwesty does know about FI he is very close...
     
  16. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    i can go back anytime i'm off friday/sat/sun/mon next weekend, zed is unsure if he can do anymore though so if i go back that's why i'm pleading for help.
     
  17. rickyrooo1

    rickyrooo1 Hanging round like a bad smell

    @davidoft yes all connected as we labelled it, originally i forgot to connect the coil power so when i found that i though ahahaaa easy fix but no....
     
  18. davidoft

    davidoft Sponsor


    Ah well perhaps possibly the earth wire in the double relay plug has broken it's connection and looks connected but isn't, the double relay maybe clicking but it could be one of the 2 relays , I usually open up the relay box and operate the fuel pump relay by hand to test the circuit .
     
  19. davidoft

    davidoft Sponsor

    I can talk you through it on the phone maybe. How far away dyou live , I'm 2-3 hours drive away
     

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