Ignition question on 911T

[Baz]

Hello everyone,

On my '73 911T 2.4 carbed Euro, I'm having starting issues. Turns over getting gas but no spark. I pulled the coil and was going to bench test it but can't find the specs to test for. Also, it has the Bosch #0221121001 but it looks like my car has a Permatune ignition, which apparently calls for a different Bosch coil. Although the car has been running fine with this one (the #0221121001) for years. I have read the past threads on converting to MSD but for now just want to troubleshoot the coil in case that's the culprit.
My questions are:
1) What are the coil test specs - primary and secondary?
2) Opinions on which coil to buy if the current one is bad

Thanks in advance!

Here's a couple pics of my car's ignition:

[HarryD]

Hi Bazza:

Since you are a newbie here, I'll cut you some slack (if you were on the Rennlist e-mail server I might not be so kind )

OK, do a search. The terms you will need are: ignition telegraph test no spark

You are looking for posts by Early_S_man. He will lay out exactly what to look for and how and why.

For your coil, Bosch says 0.4 Ohms - 0.6 Ohms for the primary winding (between the two screw terminals), and 650 Ohms - 790 Ohms for the secondary winding (between the center post and one of the screw terminals).

Warren (RIP) will guide you on the rest of the tests. Once you verifed your coil and points are ok, you will be left with the Permatune as the problem. If you can borrow a know good box, you can quickly determine if that is your problem. FWIW, Permatune offer some troubleshooting tips on their web site.

[Baz]

Thanks Harry - you are a good bloke for cutting me some slack
I'm betting my coil is kaput but will report back after testing - thanks for the testing data and links to (RIP) Warren's posts!
Cheers,
Baz

[Baz]

Also if anyone has one of these black coils FS I'm interested.
Thx, Baz

[Baz]

Hi everyone,

After removing my coil and bench testing it to find it is OK and picking up a used but working Permatune to use for trouble-shooting, I've determined the Permatune was the culprit

The Permatune was in the car when I bought it many years ago and I've never had a problem until now. So for now I will replace with this used working example and then look into an MSD setup.

I don't see any downside to converting to MSD. I certainly do not want to be stranded because my Permatune fails again. BTW, this time it didn't strand me - the failure occured while at home

Thanks to those who offered advice, especially Harry and the esteemed guru "Early S Man"!