Same starting issue

[Matt13]

So, with the help of my mechanic friend, I've got my 1973 318 Barracuda (new carb, ecu, fuel pump, battery, plugs, wires)  running pretty well. BUT, there is still an issue with the initial start. She will crank and crank with no start, but as soon as I release the key she fires up immediately. I have read from other posts this may be the ballast, so I replaced that but am still having the same issue. Ideas?

[mopar jack]

ignition switch. had this issue a couple of times.

[1 Wild R/T]

Actually a bad ballast would allow the engine to start while cranking but die as soon as the key is released to the run position..

What you are describing sounds like a possible ignition switch issue...  Theres no power getting to the coil while cranking...

[1 Wild R/T]

ignition switch. had this issue a couple of times.

I feel like an echo...

[Bullitt-]

not getting power to the brown start wire that runs to the coil, bad connection or ignition switch... Check the brown wire at the wide flat connector along the steering column and again on the engine side of the bulkhead connector for power with the ignition turned to start. If no power the switch is the culprit.
the reason it starts when you release the key is it's getting power to the blue run wire that goes through the ballast resistor

[mopar jack]

The switch is two pieces that are clamped together with punched over tabs to hold the body together and over time on the oem switches they stat to loosen apart causing poor contact on the switch points inside. When you rotated the key to start position you pushing against a return spring and this causes the body to seperate. I have had new switches fail right out of the box.

[dodj]

Actually a bad ballast would allow the engine to start while cranking but die as soon as the key is released to the run position..

or....not start while cranking and attempt to fire as you release.

Check your new ballast with an ohm meter.

[Scooter]

^^^ 3rd vote for ignition switch. I had one fail horribly in my 70 challenger. Nothing like getting in your ride, turning the key and having smoke come out of your column. Mmmmm.. the smell of melting wires in the morning. 

[Matt13]

Thanks for all the input. Considering I just put in a new ballast, I'll check the ignition.

[JS29]

Thanks for all the input. Considering I just put in a new ballast, I'll check the ignition.

But keep in mind, New means nothing. I have had defective new parts, Aftermarket and OEM.

[Burdar]

or....not start while cranking and attempt to fire as you release.

The ballast is bypassed while cranking.  Once you let off the key, the ballast takes over.  A bad ballast will not cause a "no start while cranking".

In order for the engine to fire during "start", you need power on the brown wire.  You need to test the brown wire at every electrical connection from the ignition switch all the way to the engine compartment.  You should only have power on the brown wire while the key is turned to "start".  If you disconnect the yellow wire at the starter relay, the starter will not engage while you do your testing.  Have someone hold the key to the "start" position and start testing for power on the brown wire.

[dodj]

or....not start while cranking and attempt to fire as you release.

The ballast is bypassed while cranking.  Once you let off the key, the ballast takes over.  A bad ballast will not cause a "no start while cranking".

For a single, yes. Not double. His 73 should have a double.
My car did exactly that when I had a double ballast. The 1.2ohm side was open.

[Burdar]

The four pin ballast should still be bypassed during "start".  Look at these pictures.  One side of the dual ballast is for the coil.  The other side is for the 5 pin ECU.  You'll also notice that in the other picture, the brown wire is attached directly to the blue wire in the same connector.  The brown wire directly powers the blue "run" wire during "start". 

[Burdar]

This should be how this is set up.

[dodj]

Hmm. I always thought it was a start side and a run side without really examining it. My apologies.

Now I wonder why my car behaved like the OP's car and changing the ballast  fixed it?

the brown wire is attached directly to the blue wire in the same connector.  The brown wire directly powers the blue "run" wire during "start". 

I think that is a non factory mod, or someone used blue wire where it should be brown? Or not being an e-body they used a blue coil wire?