My son's '73 Celica start problems

[70spider]

I know the car is not a Fiat, however there are some awsome people here with good mechanical knowledge.
The problem is the car will not start. We put in a Petronix electronic ignition system and it was running fine for several weeks, just a little hot on long runs and needed burped. Then out of nowhere it wouldn't start. It has fuel, but seems not to have spark. So I tested the coil with a multimeter, per International Auto instruction video, and it checked out, we cranked the engine and the rotor spins on the distributor, he changed the plugs and wires and still it will not start. I asked him to ask the folks on Gen1 Celica but he doesn't think they can help him, so I am seeking your help. What else is there?
A thought might be the wire from the ignition to the coil?
Any help would be appriciated the wife is tired of driving him to work

[riverdadd]

my aftermarket ignition ( crane) has a led that flashes with each signal..... does yours have that feature. i could be as simple as the clearance between rotor pickup and sensor pickup.... is your system optically or magnetically triggered?

[81SPIDERMATT]

I have heard if the key is left on without the engine running that it will kill the pertronix unit .. usually a mechanic at a shop will do it or kids listening to the stereo not knowing it could be a problem ..... unfortunately I have don't know how to test the actual unit itself ..... but by process of elimination you might find that has happened .... my other car is an old scout and on my other forum chasing down ignition problems a member sent me his old pertronix because of a different conversion he was doing .... but he neglected to send the magnetic ring that goes with it .... if you like I can send it to you and you could pop it in and see I guess ....I don't know much about them

[RoyBatty]

As a simple test, just reinstall the stock points and condenser and see if she fires up in that configuration. Move forward from there.

[70spider]

is your system optically or magnetically triggered?

It is magnetic.
Thanks for the sugestions I would have never thought it could be the Petronix, we'll put in the points and condensor and see what happens.
I'll post what happens.

[baltobernie]

Can't you pull one of the spark plugs, re-connect it to the appropriate lead, and hold it against a ground while a helper cranks the engine? Caution: high voltage. Wear thick rubber gloves, and grasp the plug with insulated pliers. If one plug fires, probably two or three of the others work, too.

[70spider]

Can't you pull one of the spark plugs, re-connect it to the appropriate lead, and hold it against a ground while a helper cranks the engine? Caution: high voltage. Wear thick rubber gloves, and grasp the plug with insulated pliers. If one plug fires, probably two or three of the others work, too

We did that and we checked the coil to distributor wire as well with no spark.

[70spider]

UPDATE: We replaced the petronix with a new one and it fired right up.

I have heard if the key is left on without the engine running that it will kill the pertronix unit

This is exactly what he did, he had been fiddling around with his car and left the key in the on position all night long, this drained the battery and killed the petronix and $100 dollar mistake
Thanks for the help I knew you guys would know what was wrong,