engine and drivetrain 76 2002 ignition switch issue

[Tortuga]

I have been restoring a 76 2002 for a few years now. Actually, my mechanic has been doing it. I am down to the last few issues mechanically, the most recent was a conversion kit to an electronic distributor that eliminated the points. Since then, it has been tough to start. My mechanic said it is the ignition switch. While the starter is engaged and turning the engine over it will not start, but as soon as you let off the switch it fires up. That is fine when it is warm, but now that it has gotten cold it is much more difficult.

Does it sound like my mechanic has the issue nailed?

The car is in the Triangle area of NC. I recently wrote a little blog about this past Sunday's cruise in the little bimmer. www.jamesrosemond.com

[cxzsaq]

which system did you install for the ignition?

[Tortuga]

which system did you install for the ignition?

I am not sure which system he used. I did talk to him last night and he suggested to feed the coil a direct hot line to see if it would start while the switch is turning the starter. His theory is that the switch is bad and while the starter is engaged it is not sending power to the coil. Once it is released, the coil has power and and that is when the engine starts.

[cxzsaq]

can you post a few pics of the system he had installed? you can run a hot wire from the coil/resistor but i would seek feedback from others on the forum or from the manufacturer directly (Pertronix and other manufacturers have manuals online and there are posts on this forum with guidance and application directions).

[pkchopp]

Your ignition power source is on a switched circuit instead of a constant! Simple put a test light on it and turn the key

[Tortuga]

I put a test light on the hot feed from the switch to the coil and when I turned it on the light came on, but when I advanced it engage the starter the light went out.

I ran a hot line to the coil and the ignition lights came on, even though the key was off. When I engaged the starter the engine fired right up.

Until I can replace the entire switch assembly, I installed a toggle switch in the hot line to the coil. Once she is running and the key is in the on position, I turn off the hot line switch.

I will pull off the distributor to see if I can snap a couple of pictures of the ignition system.

[Guest Anonymous]

Full voltage to the coil during cranking is supplied via a wire from the starter. Reduced voltage is supplied through a 0.9 Ohm resistance wire after the engine starts.

My guess this function was disconnected.

Take a look at the dashed line running from the starter to the coil in this schematic -

http://www.bmw2002faq.com/component/option,com_forum/Itemid,50/page,viewtopic/t,316840/

That's where coil voltage should come from during cranking.

At least disprove this possibility before dropping cash on an ignition switch.