Still trying to track down this stinking misfire!

It misfires at idle speed and generally idles rough but then smooths out after about 2000 rpm.

The engine also runs extremely rich. I installed an O2 sensor in the other exhaust pipe and hooked up a rich/lean indicator. Both sides indicate a fuel soaked exhaust.

Pickup coil?? I'll probably replace it anyway simply because I've ruled out everything else... cylinder pressure, fuel injectors, sensors, wiring... But wanted some opinions.

 

Pro,

You can check the resistance and insultaion on the pickup with your ohmmeter. Across the coil you should read between 500-1,500 ohms. From either lead to ground you should get infinite resistance (no reading).

if you are experiencing misfire or intermittent ignition, you might also want to take a very close look at the reluctor. Any cracks can cause a failure to generate a pulse on that pole, and serious rust on the reluctor can interfere with pulse generation.

There is also a filter capacitor in the base of the distributor. You can measure teh resistance of that as well. The resistance should start low, then slowly build to a higher level. If the resistance is constant or doesn't increase, you may have a shorting capacitor that is kiling pulses.

If you have an oscilloscope, you can connect jumpers to the leads of the pickup and extend them outside the distributor to test the pickup signal under actual running conditions.

 

Missfires usually show up as lean on an O2 sensor. Check your fuel pressure for too high and injectors for leaking.

Can also remove fuel pres reg vacum line from plenum and run the fuel pump. Any signs of fuel in the line and the regulator is bad. A pin hole in the diaphram will cause high fuel pressure and a rich condition.

RBob.