1985 t25 DG 1900 can not get a spark, please help

[bluelj73]

Hi, in the last couple of weeks i have fitted a recon engine, engine seems fine. We double checked tappets, the dizzy is in correct, the rotor arm points where it should on turning over the engine. The plug leads are on correctly, the tci unit is new. The starter motor is new, the coil is new, all exsisting wiring is in the correct places as the old engine as i took pics to make sure. But i cant get a spark from either the plug or coil lead on dizzy??
Please please can anyone shed some light on what could be wrong, i cant make much sense of Haynes wiring diagram and there doesnt seem to be any others i can find. Im sure the dizzy is ok it worked fine on old engine.
Would be be very grateful for any ideas !


Im missing out on all the shows !

[itchyfeet]

Have you got a voltmeter and know how to use it?
if so check you gave 12v on the coil when the ignition is on?
we can go from there

[bluelj73]

Hi, yeah i have tested and didnt get anything at the coil, Theres 12v at the plastic box next to the TCI unit where the alternator connects to the starter motor wire and it is a new battery too as the old one didnt want to charge
Many thanks

[itchyfeet]

Ok whats a tci unit?

You need to test the ignition circuit, other wires may have 12v but if there is no voltage on the ignition circuit at the back it wont run.

the black wire on the coil must have 12v with ignition on, assuming wiring is origional and not changed there is also a connection from here to the ignition module and one to the carb electrics, so with the feed from the black box thats three black wires connecting at the coil.

so if none of these has 12v then the feed from the ignition is bad, next place to check is the black box where you will find the black wire to the coil which is also joined with another black to the carb heater relay, check for 12v there with ignition on

finally no joy then pull the steeering cowling and check the black wire at back of the ignition switch for 12v with ignition on

[bluelj73]

TCI unit is the ignition module , VW Heritage call it
Right got spark to plugs now, a wire had been pulled up in cable sleeve and didnt see it. Doh!
And now hav found that the distibutor is 180 degrees out, so later i will be taking that out and putting right, do i hav to find Tdc on number 1 plug first before taking out distrutor?
Thank you for all your help, most appreciated.

Staring at the engine has made my brain numb !

[itchyfeet]

How do you know dizzy is out?
you should get engine on tdc, no1 cylinder, front right of vehicle as you look from rear plug out finger on hole and turn clockwise until you feel compression on that cylinder, then align crank pulley to timing marks which now should be close
then insert dizzy so that vac unit is towards front of vehicle and rotor arm is pointing towards centre of engine, this is also no 1 spark plug lead on cap

'Align rotor arm with notch in body' is how haynes describes it but is confusing , they mean the hole with a pressed cap towards the fuel pump as pic, most would read that as notch in rim and imo this is why people get the dizzy in wrong.

other leads going clockwise around the cap from 1 are 4, 3, 2

then you will need to adjust timing

[bluelj73]

Sorry it's the distributor drive that's 180 degrees out, we found this out, because it still wouldn't start and my mate suggested change leads 180 and it started straight away. I take it that means it's firing starting at no 3 cylinder. So now we to get shaft out and spin it 180 degrees so that it will start on no 1 making sure no1 cylinder is TDC ?

[ghost123uk]

It doesn't really matter. Many folk have their dizzy 180 degrees out and happily drive around blissfully unaware.

[bluelj73]

Hi, thanks for all your help she seems to be running ok, i think the carb may need tinkering with but ill leave that to someone who knows what there doing.
Cheers

[kevtherev]

I am in the '180 out club'

welcome in fella