Help! Abf fueling issues?

Discussion in '16-valve' started by matchowmk1, Jul 30, 2022.

  1. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    hmm. so same issues trying to pull hard it judders, and fine if you pull over for 10 mins or so

    try checking out your conversion loom ecu relay, grab a spare. when it happens immediately swap in the replacement and see if problem is solved
     
  2. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    or I guess, swap in the replacement ecu relay now then try it on a drive see if the problem is solved that would make more sense :lol:
     
  3. dodgy

    dodgy Paid Member Paid Member

    Joined:
    May 24, 2016
    Likes Received:
    1,000
    Relay ? Had one where car would get to z certain point and then cut out, usually about same distance each time, relay had got hot and desoldered itself internally.
     
  4. Tristan

    Tristan Paid Member Paid Member

    Joined:
    Apr 25, 2006
    Likes Received:
    1,205
    Location:
    Southern IRELAND
    Ok, good. Sounds like an electrical breakdown so, like the fuel pump relay
     
  5. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    It doesn’t happen when pulling hard just after a certain amount of driving as when I accelerated this time it was fine it started doing it after that when I was cruising home?

    I don’t have an ecu relay in my fuse box? I’m using a ce1 mk2 box and didn’t think they had them?

    ive tried 2 genuine old fuel pump relays in it and even bought a new top ran one just in case and hasn’t made any difference?
     
  6. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    The ce1 digifant has an ECU relay in slot 1, or it might be above the fusebox. Or not there at all, it depends how loom was made

    What about the spark module, worth a try. The original MK1 unit can be seperated from its heatsink and the MK2 unit is one piece. They do get hot so worth a look, generally reliable otherwise but can fail
     
  7. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    I don’t know if this might be linked to this problem it thought it might be worth saying in case it is,
    but October last year I was having electrical problems and opened my ecu to find some burnt pins and a blown diode, I took it to work and the sparkys changed the diode and re soldered the pins and it was fine, but I haven’t checked it since and was wondering if some thing may of happened again?
    [​IMG]

    [​IMG]
     
  8. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    I’m not to sure about the wiring as I didnt make the looms but I don’t have any relays on the top and don’t have anything in slot 1, I bought a abf ecu relay but it won’t go in slot one as the pin layout seems different?

    by spark module do you mean the ignition module? If so I’m using the small square abf coil that I think has the ignition module under it, and I replace the coil last month for a new one?
     
  9. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    For the ce1 you need a 53 in slot 1 but it would only work if the loom builder added green 2 pin plug R
     
  10. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    Ok thank you I’ll try and drop my fuse box over the weekend and have a look :thumbup:
     
  11. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    Look for the black/yellow main ECU power, though it may be difficult to find depending how the loom has been spliced as the original wire colours might be burried further up the loom. Have a look at fuses 17 and 18 in case one of those was used and has popped
     
  12. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    Thank you I’ll have a look when I get a chance bit of a hectic weekend this week:lol: I’ve defiantly not had a ecu relay in the whole 6 years the cars been built and it’s been fine up until now, could it of been wired up to not need one at all? Or how would it affect the car if I was supost to have one but I don’t if that makes sence? Sorry I’m not that clued up with relays and what they do!:lol:
     
  13. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    the idea is the ecu relay gives a nice clean power feed to the ecu switched from the main live inside the fusebox, as its run ok for 6 years your loom builder has obv just run this to a main ignition power from fusebox instead. if it was missing the car wouldn't run well at all, ask me how I know :lol:

    so yeah, check them 2 fuses they're a couple of common ignition feeds the builder may have used, either that or he'll have tapped into the main ignition live for the coil
     
  14. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    Ah lovely thank you, I haven’t had time yet but I’ll let you know what I find when I get some free time :lol::thumbup:
     
  15. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    Bit of an update, I started to strip back my engine loom back to the bulkhead to see if I can find any gremlins and I found that the earth from the head that runs down the loom and earths to the body by the fuse box has completely burnt out?
    [​IMG]

    [​IMG]

    [​IMG]

    does anyone have any idea how this would happen? I’m thinking this might have something to do with my problem.

    I haven’t finished stripping the loom all the way to the bulkhead yet but does that earth spur off to anything else between the joining plug and the fuse box? Or can I just run a new wire from the engine to the body earth by the fuse box?
     
  16. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    that is just for the MFA clocks, what may have happened at some point is your main gearbox earth was bad and the starter attempted to earth thru that wire instead. what happens in this situation depends on how the wiring was done, if it was wired to VW standard it doesn't do anything on a CE1 car as there is no path to ground thru the cluster. on a CE2 there is a link inside the cluster to a fusebox earth but all that happens is you get a burnt out circuit track on the blue clock foil rather than any damage to the wire and it doesn't actually affect clock function either.

    but by the sounds of it on your car someone earthed this wire behind the fusebox, which is why it burnt out entirely. you'll need to chase it all the way back to fusebox to see if its damaged any other wiring in the harness then go from there
     
  17. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    I’m using a ce1 fuse box, the person that made my engine loom put all the earths into 1 battery terminal? The wire that has burnt out from the head earth point under the dizzy is the brown with white line in the pic below?
    [​IMG]
     
  18. rubjonny

    rubjonny Administrator Staff Member Admin

    Joined:
    Oct 31, 2003
    Likes Received:
    3,298
    Location:
    Bracknell
    Yeah that's probably what happened. Since you don't have mfa(?) The brown/white isn't even needed, it should run to a male spade on the dash wiring near fusebox on cars with mfa
     
  19. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    I’ve started with the loom that wraps round the engine, I’ve removed it and stripped it to find that burn out earth and also found it had melted a few other wires in the loom that I’ve replaced.
    The 2 wires to the water temp sensor had splits in with bare wire exposed.
    I’ve also got a oil leak from my rocker cover that drips down the dizzy and soaks the loom below? Would this affect the wires at all if there split?
     
  20. matchowmk1

    matchowmk1 Paid Member Paid Member

    Joined:
    Jul 30, 2022
    Likes Received:
    13
    Location:
    Portsmouth uk
    Ive got a mfa stalk and cluster but it’s never worked so that explains why!!:lol:
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice