Mk1 ABF No Start / Spark

Discussion in '16-valve' started by cartertronic, Apr 12, 2016.

  1. cartertronic New Member

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    Hey guys,

    First time poster, long time reader - nice to meet you all :)

    I'm at the business end of a Mk1 ABF conversion, using a standard (golf) ABF engine, ecu etc. and have hit a road block as it won't fire [:x]

    I feel I've exhausted all options and am at a bit of a loss. HELP!

    What I got from the donor...
    [​IMG]

    What I've done... (NOTE: pic a little out of date - all sensors, loom and radiator etc. are all in now)
    [​IMG]

    I've followed the wiring guides religiously and triple checked everything is where it should be. ECU, immob, key and immob ring are all fitted.

    What I'm getting...
    The engine turns over, I can smell fuel, I get one spark from the king lead on start, but nothing after that (at plugs, leads or coil).

    I've fitted a new battery, plugs, leads as part of the conversion, and now fitted a new coil trying and solve this.

    I've tested the signal to the coil pack from the ECU and am not getting a signal.

    I've tested the crankshaft position sensor by plugging in an LED and hand cranking the engine, it lights up with each small fraction of a turn.

    I don't have a vehicle speed sensor fitted (was going to see if I get an RPM cut out before buying an aftermarket unit). However, as the car is not moving, I assume this will have no impact on start (?).

    I bought a eBay VAGCOM unit, plugged it in last night and got the below fault code (17978 - Engine Start Blocked by Immobilizer)
    [​IMG]

    According to Ross-Tech, if there is a fault with the immobilizer then the car should start for a few seconds and then cut out. However, I'm not getting that. That engine does not start at all. As above, I only get one spark from the king lead (and not consistently).

    As per Ross-Tech instruction, I've tested power to the ECU, the ECU relay, and confirmed the immobilizer wiring is correct.

    I've read various threads and this seems the closest to my symptoms, however the actual fault is unclear as the engine seems to have been refitted to another car before working..
    http://www.clubgti.com/showthread.php?271120-Another-ABF-non-starter-Help-please-deciphering-Vagcom-data

    I'm stumped! The immobilizer, key and ECU apparently all came from the same donor car (this was removed in the UK and sent to me in Australia, so I can only assume it all matches). Is there a way to confirm they match (ID codes etc.)? Is there a way to test the immobilizer?

    Help!
     
  2. Jon Olds Forum Junkie

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    Good luck.
    I rebuilt the entire engine, transplanted the engine/loom/ECU etc into another car (Ibiza) and it fired first time.
    Root cause never found.
    I still have a job lot of coils/ECU's/immob boxes and keys/fobs that I wasted good money on through this exercise.

    Well past all this now as the Ibiza is going standalone on Jenveys.

    I'm sure there will be a few boffins who will know about this 'undocumented feature' but some fixes ae kept below the radar for commercial reasons.
    (this is not a dig at anybody on this site, but merely a reflection on the efforts I made, looking back)
    Jon
     
  3. cartertronic New Member

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    Did the Ibiza you transplanted into come with its own ECU, Immob, Key, or did you use the same one that wasn't working in the other shell?

    If you retained the ECU/Immob/Key that wasn't previously working, it would indicate that there was a wiring fault that was accidentally rectified during the change over...
     
  4. Jon Olds Forum Junkie

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    It wasn't an immob/key/ECU thing (99.7% : never say never) as I had tried four full sets of the stuff by the time I decided to transplant. And every combination thereof.

    Ideally I would have tried every combination of everything I had once the Ibiza was running, but I'm the impatient type, always looking ahead to the next challenge/job
    Jon
     
  5. Bat. Forum Member

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    If you clear the fault code, does it come back?

    Might be a red herring. As you say, it ought to start, then die if the immob is kicking in.
     
  6. rubjonny

    rubjonny Administrator Staff Member Admin

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    Does the fuel pump run while the engine is cranking over, and does the isv buzz? Check the wiring loom behind the inlet, this gets baked by the exhaust and cracks up under the outer covering.

    I woudl recommend you get a proper vagcom cable, though you'll need a laptop to use it. they only cost 10 or so and are well worth it as you can then scan the ecu measuring blocks as well as looking at the fault codes.

    throttle position, inlet and coolant temps, ecu voltage plus engine speed are all worth a look. ECU relay failure is a common one, if its a ce2 fusebox you should either have a mk2 32 relay or mk3 gti 30 relay in slot 3. if its ce1 it would depend how you made your wiring loom, i often cover how to wire up the 30 relay in a socket above the fusebox.

    finally where is the vacuum pipe to the ecu connected?
     
  7. ivanro_jo Forum Member

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    If all the sensors, crankshaft position, bdc, tbc (if one of this is in bad condition you will not have sparks) are all in good condition and working and grounds connected I would check the inmo.

    On abf when you turn the key to the first position plugs make just one spark ( I dont know the reason) in all the abf swap I have made I always delete de inmo on the ecu ( swapping the inmo box keys etc always carry problems).

    I advise you to look for a 037 906 024 AB ecu (oem one without inmo).

    The speed sensor has no impact on start.
     
    Last edited: Apr 12, 2016
  8. Bat. Forum Member

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    Many of those kicking around in Spain? They are not easy to come by over here in my experience!
     
  9. ivanro_jo Forum Member

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    Yes not hard to find them, most seat toledos abf here use the AB ecu, the problem is that swaps and this kind of stuffs on mk2 are becoming very trendy here now so this ecus are the most expensive of abf ecus and most wanted.
     
  10. cartertronic New Member

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    Thanks heaps all. Been a while since I've been on a forum, forgot how helpful you guys are!

    I'm back home in a couple of nights and will get stuck in, but can answer a few now...


    Yep, fuel pump primes and isv vibrates and buzzes like my gfs second best friend


    I've got a cable, but no windows laptop. Looking at a ebay cheapy now...


    It's the original '76 fuse box with ceramic fuses, guessing that's CE1. I've tested the relays, connections and outputs again (night of post) they match below wiring diagram.


    See pic below, it runs of the top of the inlet manifold into cabin to ECU. I've tested it while starting, the pipe is drawing a vacuum.
    [​IMG]


    I've tested the crankshaft position sensor... what do 'bdc' and 'tbc' stand for?

    The grounds is any interesting one. From memory, when I wired up the standard loom there was a ground missing for the ECU and a couple of the sensors. I spliced them together and grounded them. I'll double check what they were.. I assumed I had accidentally stripped them out while separating the loom, so added them back in. It's possible I've added in a ground that shouldn't be there (but they're defo in below wiring diagram). Will double check which earths they are and come back.
    [​IMG]


    Thanks for that info. I'm leaning (or hoping) toward something else failing (i.e. my wiring or sensor) at this point. Checked on eBay the only 'AB' unit is over $500!!
     
  11. rubjonny

    rubjonny Administrator Staff Member Admin

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    the 76 fusebox is the older style, not even CE1 that didnt come in till 82. but yeah the ecu relay will have to be mounted separate to the fusebox to check which type it is and make sure its good. can bypass for testign by looping a wire between the live wire to the socket and the black/yellow ecu feed wire

    dont jump into looking at the immobiliser just yet, it isnt your issue. If the immobiliser kicks in the car will still run fine for a couple seconds then cut out, since yours isnt even gettign this far its nowt to do with the immobiliser. (that isnt to say the immobiliser is working, but we'll cross that bridge when we come to it :lol:)

    But there is no need to buy a non-immob ecu, its easy to get it working all you need is a matched immob box and chip from any post-96 mk3 golf then you code this to your ecu with vagcom. Easy!

    edit: oh and the ECU vacuum line is fine :)

    with the earth you mention, could it have been the common sensor ground? if so did test it and found it didnt have continuity to ground? if so this is normal, the sensors all earth to the ecu itself. I did the very same thing on my first ABF swap :lol:
     
    Last edited: Apr 13, 2016
  12. cartertronic New Member

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    Ah ha! I thought I was being too earth conscious...

    Just double checked the earthing. The below highlights the three extra earths I put in...

    RED = T1/A52 (ignition coil/amp earth) + B72 (lamda earth) + ECU Pin #1
    BLUE = ECU Pin #33 (this runs all the way to the large, round multi-wire plug that is bolted to the block - I spliced a wire in and grounded it)
    GREEN = K46 (engine control relay) + Immobiliser grounds #4 & #6 in black plug + OBD Port, Pin #4

    [​IMG]

    I'm guessing for starters, I shouldn't have grounded ECU Pin #33, as there was no earthing wire coming off it in the first place?
     
  13. rubjonny

    rubjonny Administrator Staff Member Admin

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    yeah ecu 33 doesnt need to be earthed, instead all the sensors earth back to it if that makes sense. I did the same as you on the 1st abf swap I ever did as when i probed it i got no ground. gave no issues once we sorted it, the problem turned out to be us being supplied the wrong immobilser box.

    the other earths you have added will only help so no worries there either.
     
  14. molegti Forum Member

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    Or to rephrase it slightly all the sensors go back to 33 and earth internally via pin 1.
     
  15. cartertronic New Member

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    I disconnected that earth (#33), started it, got a grumble that sounded like a tiny bit of ignition... then I turned the key off to try again and the starter motor wouldn't stop firing!

    I had to disconnect the positive battery lead to get it to stop. Now if I reconnect the +ve battery lead it sounds like it is spinning freely then/or a grinding noise!?

    I reconnected earthed wire #33 and still the same problem (obviously, as different circuits, but worth a shot)... can only assume something has crapped out right at the moment of starting.

    Maybe the solenoid has stuck? Or the ignition switch. Is there a starter relay on the Mk1? Fuse box pic below...

    [​IMG]
     
  16. rubjonny

    rubjonny Administrator Staff Member Admin

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    no relay for that circuit, just a wire from switch to starter. doesnt even go thru the fusebox, theres a plug behind the fusebox where starter wirte plugs to ignition wire, its the thick red/black :)
     
  17. cartertronic New Member

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    A few taps on the starter solenoid and I got the +ve battery lead back on without it starting. However, it runs on with a grinding noise until I turn the key off. I think this was the grumbling noise mentioned in the previous post. Looks like the solenoid is due.

    While tying again, the engine control relay was clicking on, but making a continuous buzzing noise while I was starting it. Didn't sound good and still no ignition.

    Tried again, the engine control relay clicks no more. Looks like a new relay is due!

    All seems quite strange, seeing as I had none of these issues until that earth was disconnected, but that earth is from a completely separate circuit.
     
  18. rubjonny

    rubjonny Administrator Staff Member Admin

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    yeah sounds liek a duff relay, either that or you are suffering too much voltage drop. might just be the starter motor is really shafted and killing your power, or your battery is too flat/dead to feed the fusebox, ecu loom and the starter
     
  19. cartertronic New Member

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    After a bit of diagnosis (including a new relay from the wreckers), figured it was the battery letting me down.

    The starter/relay symptoms described were only present when #33 earth was removed, indicating the voltage drop from the loom/sensors was too much for the drained battery. Nice one rubjonny.

    An overnight charge and it turns over as per normal, but still no spark. The king lead still sparks once and then nothing :(

    Is it only the crankshaft position sensor that is responsible for spark signal?

    Also, confirming the #7 ECU pin (start signal) is fine to tap straight into the thick red/black wire (as per below)?
    https://scontent.fmel2-1.fna.fbcdn.net/v/t1.0-9/12990989_1245290352165109_8210064478250913633_n.jpg?oh=ab3342f59a77fac159cdd73ff5bd8fbd&oe=57B8067E
     
  20. cartertronic New Member

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