Datsun Roadster Forum-311s.org

I took my 70' 2000 out last week and it was running great, but now it won't start. It has no spark. The car had the smog stuff removed when I purchased it, but still has the 17.5 distributor. It seems like most threads I've found are about upgraded ignition systems. Can anyone give me some troubleshooting steps for the stock ignition system?

I’m assuming it still turns over fine and all your gauges & lights work. If so, check the usual suspects first:

Fuses (including fusable links)
Wire connectors (tight and clean)
Ballast resistor (if you still have one)
Coil (and leads)
Points & capacitor/EI operation
Distributor & Rotor

Two electrical systems here. To add to Kai's suggestions, see if the points are getting power and are sparking when they open and close (may require an assistant to crank the engine while you look with the distributor cap off). If so, then it's likely something to do with the coil or rotor. If not, check the gap, try replacing the ballast resister on the side of the distributor (though usually they cause intermittent spark) and look for broken wires, inside the distributor as well as at the coil. Others may be able to give a more step by step... Haven't had stock stuff in years so I'm rusty.

I'd check the points dwell reading ,cranking ,check ohms on connectors
Points is a usual culprit test the ign coil ohms between neg term and pos and highV if no reading It needs a coil
Test distr to a neg body ground add a redundant wire to the distr. or a test lead , how do you know No Spark ?
The actual electrons jumping a gap are invisible the impurities in the air or some copper molecoles ignite and surround the electron have color moist air it's pretty clear
I use a peerless spark checker $20

Yep. Check the Points gap.

My guess is that its a broken lead wire hidden inside the insulation of #49 due to constant timing advance movement.
Hopefully that's it.

Cheers
Ray B.

Don't be temped to replace the lead #49 with "standard" wire, that would effect the advance curve and return to zero advance.
IIRC you can get one for pre70s chevy at most auto parts.

fj20spl311 wrote: Tue Nov 12, 2024 1:19 pm Don't be temped to replace the lead #49 with "standard" wire, that would effect the advance curve and return to zero advance.
IIRC you can get one for pre70s chevy at most auto parts.

I don't have a dizzy anymore but am wondering why a "standard" wire would cause issues...? Just curious...

Has to be super flexible and yet maintain continuity.

Jon