Rebuilt Slant 6 but No Spark help!

I just had my Slant 6 form my 67 dart Rebuilt. And I was not receiving any spark.
I bought all brand new battery cables , ground cable from engine to firewall, ballast resistor , spark plug wires , spark plugs , cap , rotor , distributor , Ignition coil and starter . Cranks over but no spark !! Help .

Let's start with "year make and model," then add "what is it exactly" you are using for an ignition system?

Breaker points?
Pertronics?
HEI conversion?
Mopar ECU?
Other?

"What have you checked?"

Voltage to coil? Voltage to coil DURING CRANKING?

Breaker points? Are they actually opening and closing? Put a meter on the coil NEG...where the wire to the dist connects. Rotating the engine at some point you should see battery voltage, more rotation should result in very low voltage at coil NEG

You MUST have a good condenser (capacitor) in the distributor

67Dart273 said:

Let's start with "year make and model," then add "what is it exactly" you are using for an ignition system?

Breaker points?
Pertronics?
HEI conversion?
Mopar ECU?
Other?

"What have you checked?"

Voltage to coil? Voltage to coil DURING CRANKING?

Breaker points? Are they actually opening and closing? Put a meter on the coil NEG...where the wire to the dist connects. Rotating the engine at some point you should see battery voltage, more rotation should result in very low voltage at coil NEG

You MUST have a good condenser (capacitor) in the distributor

Click to expand...

Is a 67 Dart 270 , I put in a two new distributor (points) , new coil, I do have voltage on the coil but no spark from the distributor. The rotor does rotate when you crack the car but no spark , I am lost here , what's your thoughts?

OK the points are simply a switch, BUT there's some "tricks."

First, suspect the high tension coil wire itself. One way to check is turn key to "run" use a grounded screwdriver (clip lead) and hold that close to the top of the coil tower. With your free hand, jumper the starter relay large exposed studs with a second screwdriver to crank the engine. This test eliminates the coil wire as a problem.

Next.......on to the distributor

1...Make sure the points are actually closing and conducting current.

2..Make sure that when the points open they are actually stopping current

"Caveats" in this mix include an open or shorted condenser, bad/ open or shorted distributor primary wire, points that are so corroded, that when closed they don't actually carry current

TO CHECK all this, put a test lamp or voltmeter on the coil NEG which SHOULD be leading to the distributor

"Bump" the engine until points are open. With key "in run" there should be battery voltage on coil NEG

"Bump" the engine until points are closed. Now, voltage and coil NEG should be VERY low, perhaps 1/2 volt, the lower the better.

Next with points CLOSED and having confirmed that coil voltage is LOW, move your meter to the coil POS. Now, coil voltage (coming through the ballast) will be LESS than battery, perhaps 7--10V. If much lower, you have a bad ballast, / bad connection in the "ignition run" power circuit. If much higher, someone bypassed the ballest

If these two voltages check out, replace the condenser. if that does not give you spark, replace the coil

+++++++++++++++++++++++++++++

If the coil voltage tests do NOT seem right, you likely have problems right there in the distributor. The dist primary wire can be broken inside, opening the circuit, it can be frayed, causing a ground short.

The points can have a problem where the insulator is damaged and grounding the connection, or they points can be corroded and never conduction.

If the condenser is either open or shorted, there will be not spark. An open condenser sometimes gives a very weak spark.

At this point, I would remove the distributor so you can spin it by hand to test. You don't want to run down your battery and starter just to check the ignition. Since a new rebuild, when you do crank the engine you want to get it started fast and running at >2000 rpm to break-in the new camshaft and lifters (before they can wear a groove, i.e. "wipe the cam"). Also, it isn't easy fooling w/ points in a slant distributor down in the dark grub zone.

To test, run a jumper from the case of the distributor to BATT-. Connect a spark plug (or tester) on the "coil HV wire", with the electrode of the plug grounded. When you spin the distributor shaft, you should see a spark each time the points open. Don't leave the points closed very long while the coil+ is powered or you can overheat the coil and points so try to stop w/ the points open. When closed, they are charging the coil's magnetic field, which only takes a few milliseconds. Break that current and the magnetic field collapses and forces current across the spark gap, building up whatever voltage is required to do so (up to 40,000 V, but less is needed in 1 atm air). Adjusting the points gap determines the coil charging time, known as "dwell angle". You get it close w/ feeler gages, then tweak with the engine running using a "dwell meter". This is all an ancient skill-set. When you tire, convert to electronic ignition where dwell time is designed-in (at least in HEI modules) and let the engineers worry about the details.