Car turns over but no spark

[DoubleA]

I recently rebuilt the motor in my 2002, while I was at it I also redid a good amount of the wiring. With everything back together now I am having an issue, the car turns over but I have no spark.

I have narrowed it down between the distributor and the coil. Voltage at the coil with everything hooked up reads 8V. When I remove the ground that is tied from the condenser to the negative coil terminal it reads 12V. Plug the ground back in and it reads 8V. 

Also, everything hooked up with 8V to positive coil terminal the points in distributor will spark. Not sure if this is good.

 

I have been testing spark with coil plug from coil to ground. 

 

I believe I have a bad condenser. I would be glad if anyone has some thoughts on this.

[flagoworld]

I believe that is normal voltage drop when the coil is charging but I might be remembering wrong. Pretty sure when you disconnect that ground it stops charging the coil so no more voltage drop and 12 volts.

 

Did you take out a spark plug and clamp it to the body while cranking to see if spark?

[dlacey]

If you have a ballast resistor then this drop to 8V when points are closed is normal.

4 hours ago, DoubleA said:

everything hooked up with 8V to positive coil terminal the points in distributor will spark. Not sure if this is good.

That also sounds normal if you mean points will spark as engine turns over.

 

From what you describe I don't see a condenser problem....but maybe the coil has an issue?

[DoubleA]

That’s what i thought too.. I’ve used two different coils now both of them giving me the same thing. Totally lost. 

[Mike Self]

Just for fun...try running a jumper wire from the coil to the distributor and see what happens...a friend and I had this same problem and it turned out to be a break in that wire that was hidden by the insulation.  It looked OK on the outside but the copper wire was broken internally.

 

The second thing to check:  Pull your distributor cap and check the carbon button in the center of the cap's interior, where the coil wire is plugged in on the outside.  It is supposed to be spring loaded.  if it's stuck or even missing, no spark will get from the coil to the plugs.

 

mike

[DoubleA]

Thanks Mike,

 

i already tried a jumper between the two, and even pigtailed a ground to the block out of that and still didn’t work… which is why I’m thinking it’s the condenser. 

that’s a good idea about the distributor cap i will check that

[flagoworld]

Did you say yet how you confirmed no spark? How are you actually checking spark?

[DoubleA]

Yes confirmed no spark, checked multiple times with one person in car cranking one outside testing.

 

have tested with the number one spark plug wire and the coil plug wire coming off coil to ground. 

[flagoworld]

How about if you take off the cap and flick the points open and closed manually? Run some alligator clips to ground and hold the other end next to the end of the rotor. Also test continuity between either side of the points when closed. A bad condenser pretty sure doesn’t cause no spark, just poor spark. Also i have zapped myself dozens of times and it’s not so bad, so do not fear! 😂

Edited February 9, 2023 by flagoworld

[Mike Self]

3 minutes ago, flagoworld said:

A bad condenser pretty sure doesn’t cause no spark, just poor spark.

Not in my single encounter with a bad condenser after 50+ years of messing with conventional ignition systems.  That bad condenser absolutely killed my spark and totally flummoxed me as I'd never encountered a bad one before, so didn't realize they would keep the spark from happening...

 

mike

[flagoworld]

1 minute ago, Mike Self said:

Not in my single encounter with a bad condenser after 50+ years of messing with conventional ignition systems.  That bad condenser absolutely killed my spark and totally flummoxed me as I'd never encountered a bad one before, so didn't realize they would keep the spark from happening...

 

mike

Ah OK... was it shorted internally then? I suppose an internal short could do that now that I think about it. Hmm .. I think a short might create a path to ground, bypassing the points and keeping the coil in a charging state.... Well, disconnecting the condenser might show that. If you disconnect the condenser and you get spark again, that would mean it's shorted.

[jp5Touring]

I've had a bad condenser leave me a half mile from home .

Progressively got worse on way home till nothing. No spark.

[John76]

More info on your car and ignition system would be helpful.

Do you have an external ballast resistor or a "sneaky" resistor wire?

If external ballast resistor, then check the function of the relay that controls the starting voltage to the coil (should be 12V).

If resistor wire is used, do you have the Black/red wire from the #15 tab on the starter solenoid connected to the (+)coil?

Do you have a 2nd black wire connected to the (-) coil?  One goes to the distributor (condenser / points). The other goes to the speed relay on the firewall behind the brake booster. This controls the dashpot. Make sure this black wire is not grounded if the speed relay/white electro-valve/dashpot have been removed.

If the above is in order, then check the condenser, wire continuity, dizzy ground, and the coil primary (2 Ohms) and secondary (12 kOhms).

 

[DoubleA]

John, 

 

I have a yellow/clear wire running to the positive coil terminal, I suppose that is a resistor wire then. I also have the black and red wire as you described.

Yes, I also have a second black wire running to the negative coil terminal.

 

I will check this out and let you know, much appreciated. 

 

[tech71]

18 hours ago, DoubleA said:

I believe I have a bad condenser. I would be glad if anyone has some thoughts on this.

It’s the first thing I would  check. Surely you have a spare to swap in?