i have an 81 cruiser that after it's been driven for a while & shut off will not immediately restart. a test light on the coil wire indicates no spark. after the truck sits for about 20 minutes it will crank right up. i think my problem is with the coil, but has anyone else had similar problems?

 

I just got done doing the same thing.
Test the ignitor, and for signal from the distributor. (cross your fingers that it IS indeed the coil).

Testing the ignitor is a process of elimination...

Use your test light and make sure that the coil is gettign 12v+ on the positive terminal during cranking, and that you get 6volts during normal 'on' (the light will be dimmer than when it was cranking). If it doesn't do that your positive wire to the coil is bad, or your ballast resistor is toast.

Teset the Coil itself.
Disconnect the distributor wire, and run a jumper wire from the battery NEGATIVE to the coil NEGATIVE. Turn the ignition on, and with a plug wire pulled, and in a place where you can see a spark, disconnect the jumper on the negative side of the coil. This should discharge the coil with a nice bright spark.

Test the distributor.
On earlier distributors with points, the distributor controlled the ground to the coil. IIRC, the later ones to the same thing, just with a coil and pickup, rather than a set of points.
Take your test light, connect one end up to the distributor wire you disconnected in the previous step, and the other end to battery positive.
Have your helper crank the engine. The light should flash.
If it doesn't flash, you need to replace the signal coil and/or pickup in the distributor.

If all of those thigns test out OK, it's time for a new ignitor.
Dealership only item and be prepared for sticker shock.

 

huh??