Intermittant no start

[mjb765]

70 383 Cuda..usually starts right up......sometimes it stalls right away and then will crank but not start. It's definitely cranking fast enough. If I wait about 10 minutes it will start up like nothing happened. Found no spark while the problem occurred and tried a new coil and new orange ign box--still nothing. Sometimes it sounds like it is about to start as I release the key from cranking. Maybe ignition switch???  Distributor module??? There really is not too much left.

If it stays running after the initial start it will run fine for as long as I want.

Any suggestions?

[Bullitt-]

The 10-minute thing throws me a bit but in general it sounds like a poor electrical connection somewhere or as you suggested a bad switch either of which is not providing power to the ignition circuit.
You say your not getting spark... at this time if you could check for power getting to the ballast resistor it would tell if this is the case.   
There are two separate wires that provide Run voltage (Blue) & Start power (Brown).. You need to check that there is +12V during cranking on the Brown wire & +12V on the Blue wire in run position.

[mjb765]

I see they go into the same connector.....so if either gets power it will show at that connector. I have checked for power at the coil during cranking and it's good--wouldn't that mean power at the resistor is there as well?

On a separate note--the electrical part of the ignition switch--is that inside the column?? It just happened this morning for a few cranks--I didn't check for power at the wires but as I let go of the key it started, so I am starting to think it is the switch.

[Bullitt-]

Power is there then it isn't throwing you off the track. 
A wire that's breaking down may measure good but not carry enough amps to energize a component.. 

What you say about it sounding like it's about to start when you release the key is similar to some reports I've read about involving power to the ignition as I described in my first reply where there is no power on the Brown wire but you get it on the Blue wire as the key is released. 

I'd be looking close at the wide flat connection at the steering column for loose or corroded connectors..  that's  one place where the power to and from the switch gets messed up

[burdar]

Like Wade said, the brown wire has power while cranking. If it doesn't start while you crank, but wants to start when you release the key, that is a classic sign of no power on the brown wire. You can disconnect the yellow wire at the starter relay to disable the starter while you test. Start at the ignition switch connector at the base of the steering column. Make sure you have power on both sides of the connector. I had a problem with loose connections there. Make sure the contacts are tight. If that connector is good, move to the bulkhead connector and test both sides there. Then work your way to the ballast.

[dodj]

that is a classic sign of

...a bad dual ballast resisitor. 

[burdar]

The ballast is bypassed during "start". If the engine starts but dies when you let off the key, that is a sign of a bad ballast. The posters car wants to start when you let off the key. That indicates a problem with the brown "start" wire.

[4Cruizn]

Ok my first question is where did you get your replacement orange box? Does it have a MOPAR sticker on it?     I had the same problem and bought a replacement orange box that was no good . . . Was a batch of them that most were faulty . . . Bought another from Mancini Racing with the MOPAR stricker and problem was cured.

 

[mopar jack]

I've had a bad ignition switch cause the same problem. Some times if I turned the key hard to the right it would start or when I returned the switch to run mode it would fire. There is a strong return spring in the switch and over time it starts to push the body apart creating a bad connection. If you pull the switch you can see it move.

[dodj]

The ballast is bypassed during "start".

Not on a dual. Which is why i specified dual in my reply. Don't know if an orange box has 4 or 5 pins. If 4 then it will not be the ballast. If it has five, then that's what I bet the problem is.

[mjb765]

Ok my first question is where did you get your replacement orange box? Does it have a MOPAR sticker on it?     I had the same problem and bought a replacement orange box that was no good . . . Was a batch of them that most were faulty . . . Bought another from Mancini Racing with the MOPAR stricker and problem was cured.

 

I had one from a previous car that was good when it was removed.

[mjb765]

Not on a dual. Which is why i specified dual in my reply. Don't know if an orange box has 4 or 5 pins. If 4 then it will not be the ballast. If it has five, then that's what I bet the problem is.

4 wire orange box....

[mjb765]

Does anybody have the wiring diagram for the electronic ignition system? Looking at mine and standing there wondering why I cant find the electronic ignition box and realizing that I am looking at a 70 Cuda diagram which didn't have electronic ignition!!!

I verified voltage to the brown on crank and the blue on run. Changed out the orange box, resistor and coil and still have no spark. I do, however have power all the time at both sides of the coil, but still no spark--is that right or is the problem the pickup in the distributor?

[73440]

http://www.mymopar.com/downloads/Ignition_System_4pin.jpg

http://www.mymopar.com/index.php?pid=115

http://www.mymopar.com/index.php?pid=81

http://www.mymopar.com/downloads/elecignconv.pdf

http://www.mymopar.com/downloads/1972/72BarracudaA.JPG

[Bullitt-]

Do you have a tachometer connected to the coil?... A bad tach can kill the system...