Suddenly....no start

[lawrencedesigns]

Now I am stumped. This project car has lots of problems, but starting has never been one of them.
First time, everytime.
I have been working under the dash, just pulling out the radio, checking speaker lines. The car has sat, and not been fired up, for about three weeks.
Went to start it today, and nothing..nada...zip. Cranks well, and smells of gas. But apparently, no spark. Pulled a plug wire, no zap to the block.
Hmmm...did the coil just suddenly lose interest? Yes, its been raining here, but its in the garage, safe and warm. Condenser suddenly die?
Where do I start looking?
Heeelllllpppppppp

[Dave at Pelican Parts]

Well, first you check for +12V on the (+) terminal of the coil when the key is on. (If you have a Pertronix or Compufire, unplug it first before you leave the key on for any amount of time with the engine off!!) If you don't have +12V there, then check the connection at the relay board. If you don't see +12V there, then check up at the wires that plug into the ignition switch, up under the dash.

...And so on. You're trying to find where the break in the circuit is.

--DD

[bryanthompson]

check the cap & rotor?

[lawrencedesigns]

Thanks for the responses. Now this is what I have found.
There is no spark from the coil.
There is 12v pos. at the coil with the key in the "on" position.
When we turn the key to ignition, the voltage drops.

Did I bugger something under the dash? Defective ignition switch?

[914GT]

Keeth

What does the voltage drop to? If it goes to zero than it probably is a bad contact in the ignition switch. If it drops several volts while cranking then it's more like corrosion on the battery terminals or resistive connection somewhere. It should be normal for it to drop a little bit at the coil because the starter is pulling a lot of current out of the battery during cranking. Maybe check your battery voltage while cranking, a good battery should hold at about 12 volts when fully charged.

[lawrencedesigns]

Ok...new coil. new rotor cap. new rotor. Still no fire.
I have the ignition switch also, but it seems to be assembled differently than the Pelican Parts help menu. I've got everything out but the lock/key mechanism. I will have to work on that.

12 volts at pos coil terminal with key on. When I crank, voltage goes to zero. Wondering if there is something else other than the switch which might be going to ground..

But this is what bothers me. When I turn the key to the full clockwise (start) position, she cranks over well, but the voltmeter indicates total discharge. Should I trust that voltmeter?

[914GT]

Put a jumper from the coil to battery and see if it starts. If it does then problem points to the switch. I'd trust a handheld voltmeter on the coil + terminal. The console voltmeter not accurate but it shouldn't drop to zero while cranking either. That would make the battery or terminal corrosion more suspect.

[lawrencedesigns]

Guy,
That did it! Many thanks. Ran a jumper from the battery to the coil. Hit the starter. Fired right up.
Must be the switch, or related wiring. Now the rest is much easier...
Thanks again..