No spark

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I have had these run me all over the place chasing gremlins.
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Or the last $200 you can spend and just be done chasing that entire ignition system.

I have never had all that much luck with oem chrysler ignition systems. On the stock-ish mopars I have owned, I leave the oe setup until it strands me the first time. And then I go with a ready to run billet distributor like the one below that is COMPLETELY isolated from anything in the car besides a wire running to a switched 12v. The distributor below is 100% stand alone, and doesn't use a ballast resistor, ignition box or anything. It operates using its own internals only.

Chrysler 273-360 c.i. SB Compatible ProSeries Ready to Run Distributor - Black Cap

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So decided to try keeping it the way it is...so here is what has been replaced: new coil, ballast resistor, cap and rotor, pick up and reluctor wheel, wires and plugs.
I have wired it correctly, only thing not replaced is the ecu.
Still...no spark.
Reminder...the motor is a 1972 318 , wiring is the 64 cuda.
Did a 1972 dodge 318 use an ecu?
Can a 2 wire distributor be wired without the ecu?
The new pick up in distributor has an orange and black wire.
 
A 2 wire factory distributor must have an external module. Not necessarily a factory module as it could use something like an an MSD box. Make sure the module has 12v power with the key in both Run and Start, and see if it sparks when you ground the pick up wires one at a time.
 
It is not clear to me what you have actually done for diagnostics. Replacing parts is not diagnostics, exactly. EG could be an issue in a connector, wiring harness, or possibly a wiring error/ old wiring hack

You need a multimeter, a 12V test lamp (LAMP not an LED) and a couple of alligator clip jumper leads. I mean that in general for wiring issues

With key in 'run' measure coil + to ground. It should NOT be full battery voltage, rather, quite low, varies from say 6--up to maybe 8v or a bit more. This shows the ECU is getting power, it is grounded, and is drawing current through the coil

Separate the distributor connector "Rig" a test gap (even an old plug) to the coil tower with a wire core wire. This can be a low voltage wire if you "hang" it in free air. Do NOT use the radio suppression coil wire. Take the connector end going to the engine bay harness, NOT the distributor. Tap the bare terminal of that connector to ground, with key in "run." Each time should produce a single "snap" hot spark.

Check inside the dist. Look for shaft play, rust/ debri, damage due to reluctor / pickup contact. If possible remove dist, but you can hook your meter to the dist pickup and crank the engine, with the meter set on low AC (not DC) volts. The pickup should generate about 1V AC

Now you must check while cranking. Wire your meter to the coil + and crank the engine using the key. The coil + should be about the same as battery. In other words if the battery pulls down to about 11V when cranking, then the coil + should be about the same, when cranking

The dist. pickup connector is especially prone to corrosion because there is no real current there. Pull it out, stck it in, feel for tightness. Get a light and inspect for crud.

Unscrew the lock screw at the ECU and "work" that connector in/ out and inspect it. At least one member here had a terminal failure inside that connector, and I have seen that years ago.

The ECU MUST be grounded. Unbolt, scrape around the bolt holes, and use star lock washers.
 
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I may have found the issue..see pics
The wiring is all new..no old wiring harness..just wiring to get engine to run. When I replaced pick up and reluctor wheel I when thru distributor and cleaned it and no play in it. Tested coil...it's good..new ballast resistor tested...good..all connectors are new and made sure they were solid.

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20241110_095733.jpg
 
Update..
I cleaned ecu plug connection.
With key on there is power to the positive side of coil.
When cranking there is power to negative side of coil...
When I mean power ..checked using test light
 
twodog45 said:
Update..
I cleaned ecu plug connection.
With key on there is power to the positive side of coil.
When cranking there is power to negative side of coil...
When I mean power ..checked using test light
Click to expand...
OK look, this here is a two way street. Please do as I asked you and post back the results. You are not looking just to see if there is power here and there ---you are looking for specific measurements. Re-read my post. Here is what you are after.

The coil may not be drawing current through the ECU. This could be because the ECU is bad, or NOT GROUNDED, or a bad connection in that cruddy looking connector.

So one more time

Turn key to run. MEASURE coil + voltage. You do NOT want the reading to be full battery voltage, because this would mean that the coil is not drawing current.

Coil NEG---Coil neg should read quite LOW, probably no more than 2V or so. If it reads battery voltage or much higher than 2V it indicates coil is not drawing current.

Did you do the tap test?

Otherwise some of us here are just wasting our time. We are glad to help but YOU need to listen and you need to respond.

You showed the gap. You need to measure it. Get yourself a brass feeler gauge. Last I knew, Oh'Really's sold them but you have to ask for them and maybe order them. Sometimes you get lucky and a set of feeler gauges will have one or two or three in there that are brass in the range you need. I've forgotten the spec it's in the service manuals. .008" I think, that is inches not metric.
 
twodog45 said:
The problem is the magnetic pickup up is out of adjustment ...do people just tweak them with a pliers?
Click to expand...
How do you know that is the problem. No you don't just tweak them. Do you know how to set breaker points? The reluctor gap is set the same way. If you look down in there is a screw to clamp one end of the assembly, with a sort of slot. You slightly loosen the screw, preferably using two screwdrivers, one in the adjust slot and one on the screw. Move it just a bit, re-snug the screw and see where the adjustment is.

You MUST use a feeler and you MUST check it that the reluctor/ pickup do not mechanically collide WHEN THE VACUUM ADVANCE moves the thing. Best way for this is a hand operated vacuum pump

I highly suggest you find a service manual. Even one for a car will cover those. Go to MyMopar and download the 72 and the 73 chassis manuals. You will have to look both in Dodge and Plymouth, as they do not post all models in all years.
 
twodog45 said:
Update..
I cleaned ecu plug connection.
With key on there is power to the positive side of coil.
When cranking there is power to negative side of coil...
When I mean power ..checked using test light
Click to expand...
What about the ECU; does it have 12V power with the key in both Start and Run? Measure with a multimeter instead of a test light.
 
I tweaked a pickup once because the gap on the reluctor was uneven, but you should be able to close the gap as said via loosen the screw and adjust.
 
Fold a piece of printer paper into quarters. Now you have a non magnetic feeler gauge. That's about .008". Just right for the pickup clearance. But I don't think that's your issue. Have you actually TRIED to adjust the pickup closer, or are you merely assuming it's at the end of the slot just from looking at it?
 
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