My 81 240 DL CIS won't crank. Getting fuel. When the coil spark is checked, it doesn't spark at all when the starter is turning, but sparks once when the key is released. Disassembled the switch and all looks ok. 6.5 volts to the coil with the switch on. Bad wiring? bad module?
bad coil?

sounds like a cranks, won't start. there's a brown wire from the ignition sw going to the starter, then to the coil. it supplies 12v to the coil while starting. when in the run position, the blue wire on the coil takes over. it's powered by the ignition sw from a different terminal and goes through the fuse box. make sure the brown wire is tight at the starter and the coil and use a meter to look for 12v while cranking. the ignition sw could be dead. there should be a resistor near the right hood hinge for the ignition. make sure all is well there, too. good luck, chuck.

I think you need to be a bit clearer with this -- you say it "won't crank" but then talk about when the starter is turning. Usually "crank" means "starter motor running." When you say it's getting fuel, does that mean the fuel pump is working normally? If the starter motor works normally but doesn't get spark, you might want to check the pickup coil in the distributor. How's the wiring? '81's are inflicted with the rotten wire problem.

What I probably should have said is that it won't "start". It cranks over fine, and usually fires once or twice when I release the key, but not while the starter is turning. When I checked the spark at the coil, it would spark once when my helper released the key (i.e. the starter motor wasn't turning but the switch was still on.)
Both fuel pumps check out ok. The wiring harness that connects in the center of the firewall looks terrible...cracked, peeling, etc. The coil ballast checks out ok.

Steve

Looks like you should probably start with the wiring then, especially the wires Chuck mentioned. You'll probably have to replace the engine wiring harness at some point. I know mine's rotten (same year) -- I'm waiting for a replacement from Dave Barton. But in the meantime I gooped up the wires around the starter with silicone. Shorts can cause all sorts of weird problems.