Volkswagen: VW Bug Starting problem, timing light, wire connections

Question
QUESTION: We finally got the VW bug to run and after driving it
around the block it all of a sudden stopped running.  It
was like someone just turned the key off.  We have checked
the coil and we get 11 volts, we put a light between the
spark plug and the distributer but the light did not turn
on (telling us we have no spark).  Why would it all of a
sudden stop working? We checked all the wire connections
but have not found anything to be loose.  Do distributer's
just stop working all of a sudden?  The rotor and points
don't seem to be black or bad in any way. Any suggestions?  
Anything else we should be looking at?

ANSWER: Wendy,
 I'm not sure about the method you say was used to check for spark.  The way I would check is with a timing light, or at least pull the center distributor wire, hold it against the distributor clip and look for spark while cranking.
 Another issue may be fuel delivery.  Look down the carb while rotating the throttle and see if you get a spray of gas.  If not, you may have a clog in the fuel lines or in the carb jets.
 Otherwise, you may want to just start from the top with a good tuneup procedure; see here:

http://www.vw-resource.com/tune-up.html

Rick

---------- FOLLOW-UP ----------

QUESTION: Hey Rick,

Thank you for the help.  We did both of what you said, we
used a timing light between the distributer and each spark
plug.... no spark at any of them.  And we held the center
wire coming off the coil near a ground and no spark.  I
believe we are getting gas (but I will check this today).  
Thank you again :)

Answer
Wendy,
  Good job with the spark checks.  Now, do the following checks:

- Power to the ignition circuit
- Cap/rotor/wires
- Points
- Coil
- Condenser

You need a multimeter for these checks.
  
- Set the meter to measure Volts DC.  With the ignition ON, there should be 12 volts at the coil + terminal.  If not, you'll need to troubleshoot the wiring; the power comes virtually directly from the battery (via the ignition switch)and there is normally no fuses inline with this circuit.

- Remove the distributor cap.  Check the rotor and cap for burned contacts and a good center spring.  Also check the wires for integrity; replace any of the above if suspect.

- Turn engine by hand and check the points gap.  It should be .016in (.4mm) at maximum opening.  Also check for burned contacts.  Adjust or replace as required.

- Set the meter to measure resistance (OHMs).  Remove the positive and negative wires from the coil and check for 3 to 5 ohms across these contacts with the multimeter.   Next remove the high tension wire from the top of the coil and check between either the positive or negative terminal and the high tension connector for about 9000 to 10,000 ohms.  Replace the coil if these do not check out.

- Now for the condenser checks.  Reconnect the coil positive wires, but not the negative (GREEN) wire.  With the distributor cap off turn the engine until the points are OPEN.  Put the meter on Volts DC.  With the ignition ON, measure for voltage between the coil negative contact and the GREEN wire going to the distributor (the wire that came off the negative coil connection.)  It should be 0 volts.  If it has any voltage, the condenser is bad or there is some other short in the points circuit.

- Turn off the ignition.  Replace all the wires on the coil.  Turn the engine until the points are CLOSED.  Measure with the meter between the coil negative contact and an engine GROUND.  It should be SHORT (0 ohms).  If not, troubleshoot a bad ground to the points or engine block.

Good luck and let me if you need anything else.

Rick