1972 chrysler 70 hp ignition help

[rangerlover]

Ok I messed up and left the key in the on position all nite when I got up there was no fire and an oily fluid coming out of the coil so I replaced it also checked the points and they are clean I have 12 volts to coil I checke my stator by testing the 2 wires that come out of it with an ohm test I need some help where to go next?

 

[Frank Acampora]

Re: 1972 chrysler 70 hp ignition help

Points are set to .014 gap on 3 cylinder models whether standard ignition or electronic ignition signaled by points. You sound like the ignition is standard points and coils. If that is the case, did you make certain that the new coil you bought was a 12 volt coil? Most auto coils are 9 volt and are used with a dropping resistor. These engines do not have the resistor and will eventually burn out a 9 volt coil.

After you set the points and replace the condenser, set timing to 32 deg before TDC at WOT. Check wiring to and from ignition switch to be certain that leaving the key on did not melt any insulation. Pay close attention to the blue wire which supplies power to the positive side of the coil and the white wire which connects the negative side of the coil to the points. BTW: when the points are closed power flows through the coil and builds up a magnetic field. When the points open, power stops, the field collapses, and the high voltage pulse for the spark is generated. The condenser serves to "cushion the power flow and keep the points from arcing.

If the engine ran before, it should run now.

 

[rangerlover]

Re: 1972 chrysler 70 hp ignition help

So if the condenser is just a cushoin I should still have alot of fire at the plugs? or does it absorb too much energy and takes away your fire?

 

[rangerlover]

Re: 1972 chrysler 70 hp ignition help

OH i think I got it if the condenser goes out the spark just arcs across the points back to the coil?

 

[Frank Acampora]

Re: 1972 chrysler 70 hp ignition help

Well, I was simplifying a little. The main function of the condenser is to stop arcing at the points and keep them from pitting and burning.

CAUTION: SCIENCE CONTENT COMING HERE!

As with anything in nature, a body in motion tends to want to stay in motion. For example, if your car crashes and you do not have a seat belt on, you body flies forward because it wants to keep going in the direction it was going when the car abruptly stopped. Electricity is no different. When the points close, the electricity starts to flow through them. When they open, it wants to keep going and tries to jump the point gap. This will cause sparking. SO: a condenser is connected to the positive side of the points and the electricity preferentially flows into it temporarily until its momentum is stopped, thus keeping it from trying to jump the point gap.

OK--You can unglaze your eyes. Science content is finished

However, since the condenser is connected to the power side of the points, if it shorts out, then you get no spark at all because the electricity keeps flowing and the magnetic field generated inside the coil can not collapse.

In older cars the frustrating mode of failure was for a condenser to short when hot. The engine would stall and cool down, the distributor would cool a bit, the condenser would no longer short to ground, and the engine would re-start and run for a few minutes until it heated up again.

In your case, if the case of the condenser looks cracked or corroded or if the wire is frayed a bit, definitely replace it. You can not test it with a regular VOM so if you have any doubts, replace it.