GTI 8v AGG. Only spark once on ignition?

[bobbito]

Hi all, can anyone help me here. Just finished replacing the head gasket/timing belt/oil+filter/fuel filter. Timed her up but won't start?
When I turn on the ignition there is a single spark but no spark at all when you turn the engine over. RAC man came out and said its the Hall sender on the side of the dizzy and recommends replacing the whole dizzy. Only other thing I have done is electrical tape round a wire which comes from the starter motor and goes behind the oil filter, as wire was showing. I think it is the knock sensor but not sure.

Any ideas?

Thanks guys

[deanpompey]

i dont think the hall sender would do that? if the dizzy were completely fubared maybe, but disconnecting the hall sender doesnt stop it from sparking, just switches fuelling to batch injection as opposed to sequential as ecu cant tell when TDC  occurs.

id be more inclined to look at coil before dizzy.

knock sensor could well stop it from starting. so maybe start there?

[bobbito]

I've replaced the coil and had it checked already. It's really odd I can't work it out.

[Wayne]

Immob. kicking in

[bobbito]

If it was the immob would it not start then stop seconds later much like starting the car with an un-chipped key?

[FlySpeck]

can you get it scanned for codes?

are you getting a constant spark from the king lead to the dizzy cap centre? If so, It could be something stupid like the dizzy cap centre contact broken or jammed in (its carbon and brittle) or the rotor arm is open circuit (less likely)

or if not, then a wire broken or plug off / dirty to the dizzy, the crank / cam sensor or the coil.

Check with a lamp or meter whether there is a regular 12v pulse to the coil (well more like 10 to 11v under cranking) and take it from there, if the coil is sparking constantly then look at the inside of the dizzy, the king lead from the coil and the diz cap.

If not, check sensor and coil wiring.

[Mikester]

Coil / imo / ignition switch.

These are all things that i have experienced causing this.

[bobbito]

I'm going to replace the dizzy and hall sender (which is on the side of it I think), when it arrives. If that doesn't work I'll try and get it on a vagcom. It's so annoying especially after doing some much work with replacing head gasket, getting the head skimmed, new timing belt and tension pulley, oil change and all filters. Now I have to drive a bloody Rover until the golf is fixed. Oh the shame!!!

[Mew]

This is exactly what happened when the hall sender went on my mk2. As soon as the ignition is turned on there is one spark, after that there's nothing. Have a play around with the hall sender connections before you replace anything

[bobbito]

Just went and had a good fiddle with the hall sender and leads + some WD and cleaned battery terminals and connecting wires but still no dice. Dizzy is in the post so will soon find out if the RAC man was right.