73 Duster only starts in "run" not start posistion

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73 Plymouth Duster

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I have a 73 Plymouth Duster that I have restored. It purred like a kitten until 1 week ago. It will only start when I let up on the key into the run position IF I get it on the right stroke. Sometimes it takes a few hits but it WILL NOT START in the "start position." I replaced the ballast resistor, ECU, Magnetic pickup, and ignition switch (pain in the butt) also redid a lot of connections to the wiring under the dash to the bulkhead connector. running electrical tests I get 9.5-10 volts on run as it should be but like 5 on start at the resistor and coil. Obviously with only 5 volts its not enough spark to start but IDK why or where it search. It's almost as if it goes through the resistor twice? maybe a shorted wire in my engine bay. I'm going to tear it apart tomorrow.

ANY help would be greatly appreciated I am sooo ready to drive it
 
first thing is to make sure the ECU has a good metal on metal ground to its mounting point. check all your grounds while you are at it.
 
Somebody else (you?) had this same problem a few weeks ago. Sounds like a problem in the "ign start" wiring (usually brown 14 awg). I think the manual calls that IGN2 on the key switch.

Disconnect the coil+ wire(s) and disconnect the yellow wire on your starter relay (so starter won't turn). Measure the resistance from BATT+ to the disconnected coil+ wire, with the key held in the start position. Should be < 1 ohm. If more, start tracing back from coil+ to:

ballast downstream side (brn wire)
bulkhead engine side (brn wire)
bulkhead cabin side (brn wire)
ign switch (IGN2)
ign switch feed (red?)

Continue until you find the main resistance. My money in on the bulkhead connector, but your new ign switch could be bad. Clean all terminals as you go with a file and spray contact cleaner, and coat with di-electric grease. You need a wiring diagram, and can find in FABO w/ a search.
 
Disconnect the wires from the ballast. Test light the ends. One set should be live in start, the other set live in run.
 
Check to see if you get these readings on your car. I got them on mine. I'd be curious to see if you read the same on yours !

I disconnected my ignition connector on the steering column from the main wiring harness. I place the ignition switch to the 2nd click (Run position)

Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN1 (Blue) and had no continuity. The new cable showed continuity.

Taking a volt ohm meter to make make some continuity checks I made measurement from the Red wire to the IGN2 (Brown) and had continuity. The new cable showed no continuity.

I think that this is the reason that your car will not start when the key position is placed to start but will start when the key position comes back to run (IGN1)

Get back to me and tell me what your findings are !
 
hey thanks guys I have been away for a while. I have been driving my car for a while and havent had time ti test any of this because it just decided to run. Yes my ECU is grounded very well i chipped paint and even double grounded it with a test wire once. Pretty much i started undoing my wiring harness and unwrapping the electric tape to inspect wires.

then I undid the coil made sure it was properly hooked up and grounded and just for grins I put in the old box to my surprise it fired right up no problem.

I have just left it and driven it like this for a week when a few days ago i decided to wrap up my wires again (worrying in the back of my mind I might screw it up) surprise surprise it wouldn't start. so I decided to tackle it again. I went and got a voltmeter undid my pos coil side while cranking...nothing. HA then I realized I have the com ground on the gauge unhooked. reattached it and tried again. I get 9.5v on start and 10.5 on run. so I hooked the wire up back to the coil and presto the car worked again. I DID NOTHING besides check voltage and it fixed it. The wires seem good but the way its acting leads me to believe something is wrong with the wiring since it fixes itself
 
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