Pertronix Help Urgently Reqd - no spark

[jamlip]

I've just fitted a Pertronix pointsless unit to my 1972 911T (carbs). I connected the red wire to the lower fuse in the fusebox (ignition-switched 12v) and the black to the two wires that fitted to the connector that used to attach to the points.

The car won't start - was fine before, albeit a bit poppy and bangy. I checked there is a 12v feed to the unit, but if I pull a plug lead from the engine and put it near and earth, when the engine is cranked, there is no spark.

Can anyone suggest what I may be doing wrong?

Urgent issue as it's now dark outside and the car is sat diagonally across the road. I can't move it because of a steep gravel driveway

[haycait911]

same engine. I've got the pertronix red to the coil + and the black to coil - . switched 12v+ also to coil +. tachometer wire (blue in pic but purple/black on car harness) to coil - .

[jamlip]

Eh? Everything I read says don't do it!

So black to coil - and red to coil +? Simple as that - no divert through the ballast or anything?

[RoninLB]

I had only one wire from the original points. You have two ?

timing has to be reset after install.

[jamlip]

My original points had one spade connector screwed to the side of the distributor. Attached to it was a double plug with two wires which both disappear off into the loom. I suppose one goes to the ballast and the other is... a tacho feed or something?

My coil only has the blue / purple-ish wire to coil + and coil - to earth...

[jamlip]

Car off the road, pushed into a public car park for the night

Where'd everyone go?!

[ljowdy]

If I remember correctly, the red wire has to go to another 12 volt switched source. Call Petronix and they will advise you as to the exact location of the wires as their wiring instructions don't cover your car..

[RoninLB]

I installed 1867 in a Bosch distributor that originally had points.

red to switched hot

black to distributor wire

[jamlip]

Cheers guys.

I spent about four hours on it today - couldn't get it to fire. Luckily, there is a Porsche specialist about 50ft from my front door, so I pushed it over there and they took a look. They were excellent - spent a few hours going over it - finally got it to kind of fire by reducing the module / magnetic ring gap to .3mm! It wouldn't start, though.

I'm wary of saying this, but I think the module itself is bollocksed - we tried everything (really!) and the car wouldn't have it. This evening I put the points back on and drove it to the garage where I keep it down the road, popping and banging and mooing like a herd of mental cows dancing on a meadow of bubble wrap.

Really quite pissed off with it now.

[RoninLB]

I disconnect any tach wiring to the unit.

These things don't last forever and they do fail so I keep a spare in the front and have my Pertronix connections at a connector block for a quick flip.

[jamlip]

Cheers for the diagram Ronin. Will try testing the unit once I have calmed down and done some work...