Would a bad coil capacitor cause the tach to read about double the actual RPM? Could this cause a fast idle condition? The reason for the question is that a friend just purchased a "D" and has had a problen with fast idle (12 to 1500 RPM measured with an external tach). The tach on the dash reads about double the measured RPM. He has replaced the idle control motor, coil, fuel pump, fuel filter and several other components. The throtle cable moves freely and the linkage doesn't seem to hang up any place. The micro switch is operating when it should. The frequency valve appears to be working in that you can hear the change in frequency as the engine warms up. He has not been able to get the dwell set due to the high idle speed. I have searched the back issues of the DMCnews & it looks like he has covered most of the bases that have been tried before. He's getting rather discouraged & I'm about out of ideas. ANY suggestions would be appreciated (well, almost any). Richard