Bit of an update. Put on the new dizzy and rotor this morning and.......... still no spark! So I went through all the ignition tests from autodata: Engine relay control: works fine ECU: Igntion on, terminals 14 and earth of wiring adapter, should be battery voltage - I Got 12.1v so fine Terminal 1 and earth, should be min 8v when cranking - I got 9.4v so fine. ECU earth connection check: Ignition off, terminal 19 and ground should be zero ohms - I got zero ECU earth connection check 2: ignition off, terminal 13 and ground should be zero ohms - I got 6.83 ohms!!!!! So here is the problem (or at least one of them) Coil - I have tried it on another car and it works fine BUT over the positive and negative side of the coil I should be getting a minimum of 2volts for 1-2 secs when the ignition is switched on dropping to 0v after that time. - Im only getting 0.11v now so this is another problem - would this be linked to the resistance I'm getting from pin 13 of the ECU? So does anybody know where terminal 13 goes or what it is? I cant find any info on it. Another thing, on removing the ECU from the car it says Digifant II on the back? I thought this set up is normal digifant? Cheers for any help once again!
pin 13 is earthed to the battery -ve, there shoudl also be a brown/white to the side of the head from ecu pin 19. pin 25 runs to the tci unit pin 6, pin 8 and 18 cgo to the hall sender, and 14 is the main ecu live from the fusebox. yeah std mk2 gti is digifant ii
I check the brown/white wire on head, that is fine so it must have something to do with the brown wire on the battery then? I've cleaned it up but I'm still getting resistance for some reason. I'll have to try a new wire
I've done a little more diagnosis today. I've found that the resistance on the pin 13 wire is only present when the coil is connected. I tried it with the coil unconnected and there was no resistance. I then checked the coil primary and secondary windings and they don't fall within the boundarys that it should but it works ok on my mates car?!?! I just don't get it at all. I've followed the wire from pin 13 and there is no splits or breaks anywhere.
2 wires above are for fan, someone has cut off the 2 pin connector housing as for pin 13, as long as its all good and is well earthed move on. main thing to do now is make sure coil is wired properly, there should be a beraided earth from head to one of the mounting bolts on coil, but i dont think this actually effects the coil itself. worth a check anyway. if coil is out of spec just try another, gsf used to sell genuine bosch coils for cheap
The braided earth is connected correctly and now cleaned. I don't quite understand why pin 13 shows resistance when the coil is connected? Anyways as you say I'll try a new coil because the current one is right anyway. At least i'll have an engine bay full of new parts by the time it is running! Ha ha. I'm also going to put new spade connectors on the coil wires as they look a bit past their best.
Tried a known working coil, still no joy. Just spoke to a chap who knows these engines inside out and he said there is a black sleeved earth wire from the ecu that should go to battery negative. I've found that inside this black sleeving is the brn/wht wire that on mine goes onto the head. Should this go to the battery? Would there be any harm in extending this wire and putting it directly to battery negative? What do you reckon?
It should not do any damage. But if you have cleaned up the earth wires then it really should not make any odds. By the way top marks for keeping at this to get it running.
yes, the wire to batter earth is the wire from pin 13 that i already told you about the ring terminal to the battery has 2 wires inside it, one from the ecu and the other from the TCI unit. there is also an extra earth wire to the head from the ecu, which is probably the one you found. There is also a wire from the fusebox to the side of the head too, so you should have the double wire ring to battery and 2 separate brown/white wires to the side of the head. if the gearbox earth is good then it should make no odds where you earth the ecu, but this is something to look at. the early mk2 earthed to the top of the upper gearbox bracket which was a poor place, so later on they moved the box earth to a stud on the rear enging -> gearbox mounting bolt. If you have the early style or it looks a bit rough you may want to upgrade to mk3 golf battery cables as they're much thicker and a better design. the only possible thing is the earth to the battery tray wont reach on the mk3 cable, if so you just need to make up a chunky earth cable from here to the battery
Ahhh well in that case I am missing at least two earth wires! The pin 13 wire doesnt go straight to the battery it has been cut and spliced into the brn/wht wire that goes to the head! I think what I'll do is extend and run all the earth wires to the battery negative and re-clean all the earthing points again! This needs to be running by the end of the week as im losing my patience now! I'm tempted to rip everything out, stick some carbs on it and start from scratch!
reet: ecu pin 13 - brown -> battery -ve tci pin 2 - brown/white -> battery -ve ecu pin 19 - brown/white or brown/black -> side of head fusebox pin g1/5 (or spade behind fusebox if ce1) - brown/white -> side of head
