73 240 No spark

[Shawninvancouver]

power to coil , put a new coil in and coil gets voltage when key is turned to start car position... but nothing getting past the distributor... what should i look at in the dizzy? can you look at wires to coil.. looks like its wired correctly.. do points look ok? does the distributor look like toast?

[Shawninvancouver]

any ideas here?

[DatsunZGuy]

I would look at the ballast resistor for starters.

 

[Zed Head]

This video might help.  It's a starting point anyway.

 

[zKars]

Basics basics basics. You’ve checked the power to the + side of the coil. Good.  Do the points open and close as the dizzy rotates? Are the contacts clean? Bit of sand paper in there dragged through to scuff them a bit. There is a gap spec, 0.018 or so? 

The terminal that connects to the dizzy that connects to the points. Is it dirty? Does it fit snug? Put it on and off a few times to scrape it clean, 

Start there, report back

[Shawninvancouver]

Cool. Ok.  I am going to do all that. I have a few questions before I start. 
a. Will the points work for a short time without the condenser? Just for spark testing 

b. Will I get spark if I remove the ignition coil condenser ? Or is that needed for spark? I read I can run engine for short time without that condenser. 
 

c  will I get spark with a bad ballast or no not??

D could the plug wire from coil to dizzy be bad? I tried testing it with test light and it would not let power through it  if I connected test light to it  then put one end to pos battery and one end to neg battery should my test light light up?? Or is that special wire in those plug leads ??

 

[Zed Head]

15 hours ago, Shawninvancouver said:

coil gets voltage when key is turned to start car position... but nothing getting past the distributor

Seems like you might be misunderstanding how the igntion system works.  It's kind of magical.  The spark does not come directly from the power that enters the coil.  It comes from the collapse of the magnetic field when the power through the coil is interrupted.  The part that you need to focus on is called the primary circuit.  It's the current that enters the coil, passes through the points and on to ground.  The condenser does not pass any current, it is connected as a branch on the circuit to absorb the peaks of the current pulses as the primary circuit is opened and closed.

Anyway, the places to probe for voltage are the two posts on the coil and both sides of the points.  You also want to check the grounding of the distributor body since that is where the current flows after it passes through the points.

The most common problem with old points is corrosion on the contacts.  Open the points and file these surfaces.

[Shawninvancouver]

Cool. Ok.  I am going to do all that. I have a few questions before I start. 
a. Will the points work for a short time without the condenser? Just for spark testing 

b. Will I get spark if I remove the ignition coil condenser ? Or is that needed for spark? I read I can run engine for short time without that condenser. 
 

c  will I get spark with a bad ballast or no not??

D could the plug wire from coil to dizzy be bad? I tried testing it with test light and it would not let power through it  if I connected test light to it  then put one end to pos battery and one end to neg battery should my test light light up?? Or is that special wire in those plug leads ??

 

[Zed Head]

Forums are give and take.  It's your turn to give.  Good luck.

Edited April 28 by Zed Head

[Shawninvancouver]

Ok. Thanks.  When the key is turned on, not to start the car. Just for power. I do get power to the coil.  Both pos and neg have power.  When trying to start the car I have power leaving the front of the coil.  I am nit sure if I have a dead plug wire going from front of coil to dizzy.  I tried to test it and will test it again.  Ok I had sanded points before and no luck. Sanded top of thing that spins in the dizzy. Had no spark.  Ok so I don’t need to buy a new condenser that sits beside dizzy. Maybe will try a new dizzy.  Does it help to buy a spark plug test light?? Should I spin engine to see if dizzy is spinning and opening and closing points?

[Shawninvancouver]

Woops. Think i posted that by mistake.  

[Zed Head]

Do the points open as the distributor turns?  And do they close completely?  They have to open and close to create a spark.

You can remove the condenser and try.  It might be shorted internally.