[924] don't start anymore. Need help.

[cturle]

Hello,

i have a problem with my 924 (year 81, transistorized ignition). It doesn't start anymore since last week.

last friday, i cranked 2 times, starter ok but the car didn't start. The third time, it starts nicely and i drive home (4km)
saturday, i cranked and the car started nicely then i stopped.
monday, i cranked, starter ok but the car don't start anymore.

Test 1 :
I shunt 30-87 of fuel pump relay => fuel pump ok.

Test 2 :
fuel pump relay out to not flood the engine.
I take off one spark plug. I crank => no spark.


Test 3 :
fuel pump relay out to not flood the engine.
I take off one spark plug but plug it directly on the coil (terminal 4). I crank => no spark.


Measures :
resistance between ignition coil terminals 1 and 15 : 2,5 ohms
resistance between ignition coil terminals 4 and 15 : 7 KOhms
tested spark plug cable resistance : 2KOhms
distributor/coil cable resistance : 2KOhms

With ignition on.
voltage between ignition coil terminals 15 and ground => 6,45 V
voltage between ignition coil terminals 15 and 1 => 5,02 V
voltage between ignition coil terminals 1 and ground => 1,43 V

Can you help me ?