More ignition issues on the dart

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SpriceyStuff

SpriceyStuff

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Hey guys. I have a 74 Dart Sport, Electronic ignition. I’m having an issue all of a sudden where I’m not getting spark. If I disconnect the distributor wire and touch it to ground, I get sparks out of the coil wire. But when I plug it all back in and turn the key, I get one spark when the engine starts cranking, and one spark when I let off the key. So the engine sits there and cranks and does nothing, but occasionally if I let off at just the right time it’ll fire exactly once… what’s the deal? Anyone else had this issue? I’ve tried jumping out the ballast resistor, but to no avail
 
My first thought is poor connections at the distributor connector--work it in/ out several times--or the pickup is bad. Hook your multimeter to the distributor connector and set to low AC volts. Cranking the engine, you should see about 1V AC
 
67Dart273 said:
My first thought is poor connections at the distributor connector--work it in/ out several times--or the pickup is bad. Hook your multimeter to the distributor connector and set to low AC volts. Cranking the engine, you should see about 1V AC
Click to expand...
Alright I’ll give that a shot when I get off work. I really hope the pickup isn’t bad cause I don’t feel like dropping $120 on a new distributor. I tried working the connections and even used cotton swabs to clean them out.
 
You have 12V at the ballast input with key in run? Also make sure the ECU case is well grounded.

When I bought my latest car it was having similar problems. wouldn't start etc. or try to fire when releasing key.
Found the dual ballast installed backwards (the notch wrong way) ran a ground wire to ECU case and timing was also crap.
 
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Years ago I had a similar problem with a Volare. After several tries of trying to start it by releasing the key it finally started. After the engine warmed up and the ammeter died down I drove it home. I was tired and the family was too so off to bed. Next morning I grabbed an old rusty ECU, a phillips, and a jumper wire with alligator clips and tested it. Varoom! Installed it. Bought a new ECU and swapped it in. Kept the good old ECU in the glove box along with a phillips and a 7/16 wrench. Never had to use it.
 
I never followed through, but I was playing with the idea of picking up a .177 caliber rifle cleaning brush, AKA brass or stainless bristle brush to clean those and trailer connector terminals.
 
crj1968 said:
You have 12V at the ballast input with key in run? Also make sure the ECU case is well grounded.

When I bought my latest car it was having similar problems. wouldn't start etc. or try to fire when releasing key.
Found the dual ballast installed backwards (the notch wrong way) ran a ground wire to ECU case and timing was also crap.
Click to expand...
I got about 9.5-10.3v at ballast on both sides
 
pt70 said:
Years ago I had a similar problem with a Volare. After several tries of trying to start it by releasing the key it finally started. After the engine warmed up and the ammeter died down I drove it home. I was tired and the family was too so off to bed. Next morning I grabbed an old rusty ECU, a phillips, and a jumper wire with alligator clips and tested it. Varoom! Installed it. Bought a new ECU and swapped it in. Kept the good old ECU in the glove box along with a phillips and a 7/16 wrench. Never had to use it.
Click to expand...
Yeah I double checked the ICM to make sure it was grounded good. I even tried another new one I have in the trunk. No dice
 
I'm having something similar. When I get a chance I'm gonna test the coil.
I thought it was a carb or timing problem. I just happened to leave timing light hooked up and tried to start it. No flashing(no spark)...
 
Is the vac adv hooked up? If so, the p/up wires flex when it operates & they eventually break.
Wiggle the wires while checking with an ohmmeter.
 
SpriceyStuff said:
I got about 9.5-10.3v at ballast on both sides
Click to expand...
OK both sides like across the ballast in the long direction- right?

If that's the case... then with the key in run position, it may start by by jumping the solenoid.
If it does then distributor, ECU etc all OK...
If it doesn't then more troubleshooting in order
 
Well as of now, it looks like I have 9.3v in run circuit both in run pos on the switch and in start pos it goes down to about 4.35v. The start circuit gets 5.4v ish and stays the same with key in start pos. Does this mean my ignition switch is broken? I’m hoping now cause it’s a major pain to replace…
 
SpriceyStuff said:
Well as of now, it looks like I have 9.3v in run circuit both in run pos on the switch and in start pos it goes down to about 4.35v. The start circuit gets 5.4v ish and stays the same with key in start pos. Does this mean my ignition switch is broken? I’m hoping now cause it’s a major pain to replace…
Click to expand...
Sounds like you're losing the ignition 2 leg in the start position. Time to start tracing wires.
 
SpriceyStuff said:
Well as of now, it looks like I have 9.3v in run circuit both in run pos on the switch and in start pos it goes down to about 4.35v. The start circuit gets 5.4v ish and stays the same with key in start pos. Does this mean my ignition switch is broken? I’m hoping now cause it’s a major pain to replace…
Click to expand...
Where exactly are you measuring this?

Do THIS exactly

Clip you meter to coil + and ground. Turn key to "run" and measure coil to ground. It varies should be somewhere between 5- 10V. Now crank the engine using the key and watch meter, read while cranking. You should see full battery voltage less the drawdown from the starter, about 11V. If any doubt, move your meter to the battery POS post and again, read while cranking. The two readings should be substantially the same
 
HOW THE IGN1 / IGN2 circuits work

1....The "Run" line from the key is hot ONLY IN the "run" position. It is DEAD during ACC or "START". DEAD

It feeds through the bulkhead, and depending on year/ model, feeds the ignition system via the ballast resistor, branches off to feed the light blue field wire to the alternator, the power terminal of the ignition box, the IGN terminal of the VR, smog doo dads on some years. IT IS NOT fused

The ballast on 4 terminal resistors, feeds the + side of the coil (just like breaker points) and the other side feeds the ECU box. THIS IS NOT USED with the later boxes, known as "4 pin boxes" which can use EITHER a 2 or 4 pin resistor

AGAIN THIS RUN POWER GOES DEAD during start

2....The IGN2 line is fed from a separate dedicated contact off the igntion switch JUST like the "start" wire. When the key is twisted to "START" the yellow start wire is live and triggers the start relay

The (normally brown) bypass/ IGN2 wire feeds from the ign switch, through the bulkhead, and to the coil + side of the ballast resistor. THIS IS LIVE IN START

HOW DOES the ignition box get power during start??? With power fed to the + side of the coil, power is BACKFED through the ballast resistor to the ECU box during cranking. So the box does NOT GET full battery power during cranking but the coil DOES so
 
RustyRatRod said:
Sounds like you're losing the ignition 2 leg in the start position. Time to start tracing wires.
Click to expand...
Well according to my diagram, my yellow wire on the switch goes to the starter relay, and I know that works cause it cranks. But there is a brown wire that goes from the switch to the ballast and then to the coil so I need to check the bulkhead for corrosion and check to make sure the switch itself is actually directing the power to that wire. I’ll let you know in a bit
 
67Dart273 said:
HOW THE IGN1 / IGN2 circuits work

1....The "Run" line from the key is hot ONLY IN the "run" position. It is DEAD during ACC or "START". DEAD

It feeds through the bulkhead, and depending on year/ model, feeds the ignition system via the ballast resistor, branches off to feed the light blue field wire to the alternator, the power terminal of the ignition box, the IGN terminal of the VR, smog doo dads on some years. IT IS NOT fused

The ballast on 4 terminal resistors, feeds the + side of the coil (just like breaker points) and the other side feeds the ECU box. THIS IS NOT USED with the later boxes, known as "4 pin boxes" which can use EITHER a 2 or 4 pin resistor

AGAIN THIS RUN POWER GOES DEAD during start

2....The IGN2 line is fed from a separate dedicated contact off the igntion switch JUST like the "start" wire. When the key is twisted to "START" the yellow start wire is live and triggers the start relay

The (normally brown) bypass/ IGN2 wire feeds from the ign switch, through the bulkhead, and to the coil + side of the ballast resistor. THIS IS LIVE IN START

HOW DOES the ignition box get power during start??? With power fed to the + side of the coil, power is BACKFED through the ballast resistor to the ECU box during cranking. So the box does NOT GET full battery power during cranking but the coil DOES so
Click to expand...
Okay so as it sits, I get about 7v to the IGN2 wire from the switch. My RUN wire voltage cuts in half but doesn’t go dead. Is this why I’m not getting my full voltage to the START circuit? Is this indicative of a short in my switch?
 
67Dart273 said:
Where exactly are you measuring this?

Do THIS exactly

Clip you meter to coil + and ground. Turn key to "run" and measure coil to ground. It varies should be somewhere between 5- 10V. Now crank the engine using the key and watch meter, read while cranking. You should see full battery voltage less the drawdown from the starter, about 11V. If any doubt, move your meter to the battery POS post and again, read while cranking. The two readings should be substantially the same
Click to expand...
I tried this just now. I show a little over 5v. Goes up to about 6.5v while cranking. Battery is dying. Cranking getting slower, voltages are going down. Coil + voltage was a littler over 9v earlier
 
Well first thing you need is a good and charged battery. Make sure battery cables are in good shape.
 
I had some time to mess with the car yesterday. I pulled the switch out of the column and I see that my 6 month or so old switch is already starting to come apart a little. It cranks with the switch. I get about 9v out of the IGN 2 wire. I forgot to check and see if the run wire is dead or not while cranking. If it doesn’t go dead I’ll assume the switch is faulty and warranty it. What else should I be looking for? I’m starting to have an issue with the bulkhead too I think. Need to figure that out. Might end up replacing the bulkhead connectors entirely
 
Right now I am getting about 10.5-11v to the ballast while cranking. Still no spark. Can’t figure it out
 
One thing I’ve noted is that when Turing the distributor, I get no spark at the coil, but I do get spark at the coil when grounding the wire that goes to the distributor. This seems to implicate the pickup in the distributor. What do you guys think? Particularly @RustyRatRod you seem to know a lot about these ignition systems. If I hook everything up It sparks when the switch hits “run” but that’s the only time. So I can wiggle the switch back and forth in the run position and watch the wire fire. But that’s it
 
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