Checking speed & reference sensors
 

Trying to check these sensors on 88 Carrera, as per Bentley 200-5. I can get a feeler gauge into the top gap (reference), but no room to gap the bottom one (speed). Any helpful tricks here? Any way to test if the speed sensor is working properly, other than looking for a sine wave on an oscilloscope (Bentley 200-16). I don't seem to have one in my toolbox.

If the engine starts and runs they are working. Adjusting one sensor sets the gap for the other one.

Best time to check them is if the engine is out. Otherwise should never need to touch them.