E21 315 no spark

[Sel The Don]

Getting to the end of my wits with this car, one thing after another.

Now I'm getting no spark so hopefully someone can chime in and put me out of my misery.

A little bit of info;

Spark control unit: 0227 100 111
Getting 12 volts from the green wire Into the control unit.

Yellow wire to the impulse sender im getting 1.5 volts, no fluctuation when cranking.

Black wire to the impulse sender flits between 1.3 and 1.8 volts when cranking, no fluctuation otherwise and 1.5 volts

Black wire to the coil (- terminal), fluctuations between 0.3 and 1.3 volts when not connected to the coil and cranking, showing 12 volts when connected to the (-) Terminal. Fluctuations of 8.3 - 8.4 volts when cranking.


Coil: 0221 122 319
(+) Primary, 12 volts when connected
(-) primary, 12 volts only when (+) is connected

Resistance across primary 1.5 ohms, resistance across primary and secondary around 7k ohms.

Someone please help, I've spent days trying to figure it out and am getting nowhere.
Can give any other info if needed.

[Jeroen]

FAQ section - Electrical (including ignition) for starters...

[Jeroen]

And for testing the impulse sender: should generate > 0.05V over pins 7 and 31d while cranking. If not, impulse sender is likely to be dead. Otherwise the control module may be defective, see FAQ, a bad ground connection can fry it.

[Sel The Don]

Thanks for the info Jeroen.

I've checked the grounds and they are all fine, there was one that wasn't connected though. It was the one on the drivers (LHD) chassis rail going to the engine block, that's been connected now.

Impulse sender - should it be a pulse or a constant voltage? I'm getting a pulse from the black wire but it's way over the 0.05v that you are saying, although I'm testing to ground and not across the pins.

[Jeroen]

Better follow factory instructions for testing pulse sender, should be pulse indeed, anything over 0.05V is ok.

Grounding: see FAQ, it's not the ground strap but a bad ground AT ignition control module that kills it. Screws that take care of ground to cooling body and ground to chassis (1 screw each).

[Sel The Don]

I tested with your method and found a pulse.

Our local motor factor had a new ignition module so I bought that and now she runs!

Just have to now figure out how the wiring works for the air valve (always supposed to have 12v to it?) and pulldown unit (not engaging) and I'll be set!

Thank you so much Jeroen for your help. Respect.

[Jeroen]

Good news, you're welcome! As for carbs... hardly any knowledge on these so I hope one of the other experts will chime in now

[Sel The Don]

Great news, yes!

Would be great if anyone with the knowledge can chime in with regards to the carb I'd be a happy bunny!

[uwbuurman]

Cool nice that it runs. Peter V. is the carb specialist n⁰1 here. Drop him a pm or just wait 'till he drops by, here.