No Spark...

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olddog12

olddog12

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I have a 318/727 with points. Ive done some searching on here and did some checking and here is what I have found. BTW, all the wiring is original but has been taken apart or completely gone through. I am very electrically challenged also so please speak as if you were teaching your 10 year old lol.
Something that is odd...when I turn the key from run position back to auxiliary, the spark plug I have laying on the manifold would spark once a nice blue spark, did that three time with the key and cant repeat now??

Anyway I found this from 67dart273 in another thread and here is what Ive got so far.

1....Must have power to the coil when cranking. "Rig" your meter to the coil+ and watch the meter while cranking the engine USE THE KEY to do so, do not jumper the starter relay. You should have within a couple of tenths of a volt as 'same as battery.'. So after you read the coil+ / cranking, measure at the battery terminals. You want at least 10V or more
coil + side is 9.00 and battery is 12.58
2....You have "sort of" determined the coil is good, as you switched the coil

3....If you do NOT have voltage to the coil, you can simply jumper a clip lead to a batterysource, like the alternator output stud. DO NOT leave this hooked up longer than needed, you can damage the points and even the coil
is 9.00 v enough?
4...After you get 1---3 above, determine if the points are conducting when closed, and opening. Turn the key to "run." Bump the engine round until the points are CLOSED. Measure both coil+ and coil --. You should have very LOW voltage at coil neg, and about 6--9 at coil POS
coil + is 10.30
coil -- is .535
If you have this,.......

Bump the engine until the points are visibly open, and re-check. You should have "battery" at BOTH coil NEG and at coil POS
here im getting coil + 10.4 and coil -- is 1.30. Battery at 12.30
If you have this, chance the internal condenser (capacitor) inside the distributor.


Any suggestions on what to do next?
 
Make sure that your grounds are good...

Take the connections apart and scrape any paint off the surfaces, then put them together...
 
Also forgot to mention, I tried opening the points with a screw driver and could not see any spark. I have a new mopar dist. cap and button, I changed the button with no change, I was gonna change the cap but the wires which are also mopar seem almost to easy or kinda loose when I put them in so didnt change it.
I also took the ecu off and made sure it was grounded good. I have a ground from front of the block to rad support and one on the driver manifold to the master cylinder bolt. I have 12.58 v at the little box by the battery (im drawing a blank on its name)
 
Thanks for the reply kracycuda, I took them off and cleaned each with a dremel to remove any paint.
 
I just had a no spark issue with electronic ignition, and it turned out to be the grounds and a faulty new wiring harness...
 
olddog12 said:
Also forgot to mention, I tried opening the points with a screw driver and could not see any spark. I have a new mopar dist. cap and button, I changed the button with no change, I was gonna change the cap but the wires which are also mopar seem almost to easy or kinda loose when I put them in so didnt change it.
I also took the ecu off and made sure it was grounded good. I have a ground from front of the block to rad support and one on the driver manifold to the master cylinder bolt. I have 12.58 v at the little box by the battery (im drawing a blank on its name)
Click to expand...

ECU??? With points???

There is no ECU with points... Only electronic ignition...


Trace the path with a test light. Check for power at the ballast resistor input, then the output (should be about half of battery voltage), then at the coil positive terminal.

If you crank it over with the coil output wire close to a ground, does it spark from the coil??? (Disconnect the center distributor wire and hold it near a ground and check for spark). This will see if you are getting spark from the coil...
 
I dont have a test light only a volt meter. Should these be checked with key on or while cranking?
 
I'm so confused,

I don't even see that you stated the problem.
I'm thinking it's intermittent loss of spark ?
With the Chrysler Electronic Ignition System
The One-Spark at the key cycle is normal, and I use it as a test proof. That is to say,If you see the one-spark, then the following items are good; the ECU and it's ground, the coil, the ballasts,and most of the wiring. The coil is tricky, cuz it can pass this test yet fail after running as it heats up.
But the One-Spark test does not prove the magnetic pick-up, it's circuit or the triggering of it by the reluctor.
If the One-Spark test stops working,or is intermittent, as it seems to have for you,I would suspect the power supply circuit to either the ECU or the coil.In this case, every single connection has to be examined, and the dual-ballast resistor is prime suspect #1. Because they are cheap, I keep a spare in the gb at all times.The resistor is nothing more than a coil of resistance-wire encased in a ceramic block to protect curious fingers, and isolate it from the vehicle ground. When electricity passes through it it gets hot.As it heats up it's resistance to that electricity increases and the voltage falls. The voltage-in,is always near battery voltage (coming from the ignition sw). The voltage-out, can vary from near-battery when cold, to about 60 to 70 percent of battery as it reaches it's running temperature.Because of the way this item works it has a hard life.They don't last forever.At the first sign of trouble I just slam a new one in;Right after I clean the ECU ground.Then I cycle the key to prove the OneSpark test.
 
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This may help.
The blue wire that goes to the voltage regulator has power at the bulkhead but not on the plug end.

IMG_3457.JPG


IMG_3458.JPG


IMG_3459.JPG
 
No voltage on the blue wire at the VR with the key in"run", but with the voltage at the bulkhead, probably means a problem at the splice. Check for power at every other blue wire under the hood.If they are all dead, the problem is between the splice and the bulkhead. If just the VR is dead, then follow that wire to the splice and repair it at the break.
This circuit is tricky tho. You have to pull a current through to really prove it. Your voltmeter can register good voltage because the pressure is there. The voltmeter doesn't know tho if there is a good electron flow possibility. And all electrical items need varying amounts of electron flow, at the prescribed battery voltage. So that means you need a test light, and not one of those little trailer wiring testers. Years ago I made one using a motorcycle headlight bulb. I like it cuz I can see a problem when the bulb intensity is not what I'm expecting it to be. But I have also used any old automotive 12 volt bulb like a stoplight or signal bulb.
The point is to suck some juice through that circuit, to prove the entire circuit will support the ignition system.
This circuit starts at the battery plus post and ends at the battery minus post. It goes something like this;
B+ to start relay to fusible link to bulkhead to ammeter to ignition sw, back through the bulkhead, to splice. From splice it splits 3 ways. Leg A, to VR to ground to battery-, and Leg B, to electric-choke if you have one,to engine and back to battery- and Leg C, to the ignition system,to the body or engine,and back to battery-. The splice is under the hood somewhere near the distributor and buried inside the harness.
The ignition system starts at the Dual-ballast resistor, and goes like this;
Leg A,blue wire into resistor A-side to ECU to body to battery-,and Leg B, blue wire into resistor B-side to coil + to ECU to body to battery. The ECU takes the tiny signal generated by the trigger inside the distributor, and uses it to fire the coil.
In your case; it looks like you have a master disconnect at the back of the engine on the passenger side, so some of these connections will also pass through it. The engine should have a braided un-insulated ground strap running from the back of the passenger head to the firewall. There should be an insulated small gauge wire running from the battery negative to the radiator core-support near the driver-side headlamp.
Those quick crimp-connectors, such as what I see at the coil should be considered temporary. They work just long enough to get you into trouble.
 
Last edited:
olddog12 said:
I have a 318/727 with points. Ive done some searching on here and did some checking and here is what I have found. BTW, all the wiring is original but has been taken apart or completely gone through. I am very electrically challenged also so please speak as if you were teaching your 10 year old lol.
Something that is odd...when I turn the key from run position back to auxiliary, the spark plug I have laying on the manifold would spark once a nice blue spark, did that three time with the key and cant repeat now??

Anyway I found this from 67dart273 in another thread and here is what Ive got so far.

1....Must have power to the coil when cranking. "Rig" your meter to the coil+ and watch the meter while cranking the engine USE THE KEY to do so, do not jumper the starter relay. You should have within a couple of tenths of a volt as 'same as battery.'. So after you read the coil+ / cranking, measure at the battery terminals. You want at least 10V or more
coil + side is 9.00 and battery is 12.58
2....You have "sort of" determined the coil is good, as you switched the coil

3....If you do NOT have voltage to the coil, you can simply jumper a clip lead to a batterysource, like the alternator output stud. DO NOT leave this hooked up longer than needed, you can damage the points and even the coil
is 9.00 v enough?
4...After you get 1---3 above, determine if the points are conducting when closed, and opening. Turn the key to "run." Bump the engine round until the points are CLOSED. Measure both coil+ and coil --. You should have very LOW voltage at coil neg, and about 6--9 at coil POS
coil + is 10.30
coil -- is .535
If you have this,.......

Bump the engine until the points are visibly open, and re-check. You should have "battery" at BOTH coil NEG and at coil POS
here im getting coil + 10.4 and coil -- is 1.30. Battery at 12.30
If you have this, chance the internal condenser (capacitor) inside the distributor.


Any suggestions on what to do next?
Click to expand...
 
I would seriously consider a hei conversion. If you leave the key in the on run position(not starting) and the ponts are closed you will burn them up
 
Not sure of the resistance that it should have, but you can google it. It is always suggested to have a spare as it is a weak link. That is why i convert to hei ignition, no ballast resistor needed
 
The OP wrote this; the bold letters are his measurements, and the italics are 67Dart273's:
Bump the engine until the points are visibly open, and re-check. You should have "battery" at BOTH coil NEG and at coil POS
here im getting coil + 10.4 and coil -- is 1.30. Battery at 12.30
If you have this, change the internal condenser (capacitor) inside the distributor.

If you are 100% for sure that the points are open in the above measurement, then indeed the coil - is shorted/partially shorted to ground somewhere, and I can think of 4 possible reasons:
1. Your condensor is shorted. Disconnect it and see if the coil - voltage rises to equal coil + voltage with the points open. If this happens, change the condensor out per Del's original notes that you found.
2. One other possibility is if you have a tach connected to the coil -; disconnect that and re run the above test and see if the coil- is still 1.3V. If the coil - is now the same as coil + with the points open, then the tach is shorting the points.
3. Sometimes, points can 'grow' a 'nub' of metal on one side that can short out to the other side despite the points looking open. So remove the points and examine the points' surfaces to make sure they are smooth. If not, then smooth them with fine sandpaper or crocus cloth; use a very fine emery file on any 'nubs'. (You used to be able to buy very fine 'points files'.)
4. There is a short of the coil - wire to the distirbutor case where it goes into the distributor.

And measure the gap between the points at maximum opening with a feeler gauge; it should be in the .017"-.018" range.
 
As to the ballast, if it gets hot, with the key in run, it is working. It takes a few minutes. This is better than a resistance test, cuz it means something downstream is pulling a load through it. However the ohmeter should show less than 2 ohms, through either side, with it removed from the circuit.

nm9
He changed his story in post #7. Now it's electronic,and the pics in post#10 prove it.
And he still has not stated his problem.
 
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olddog12 said:
How do I check the ballast?
Click to expand...
1st, put your your ohmmeter leads together and measure the resistance of the leads only. Do this a few times and get an average number; lead resistance is usually well under 1 ohm.

Then disconnect 1 end of the ballast from the harness and measure resistance across the ballast terminals. Then subtract the lead resistance that you got above. This is the actual ballast resistance. With the low resistances involved, it takes some care to get an accurate reading.

The correct OEM ballast is 0.5 to 0.6 ohms, when the ballast is cold. It will rise to a bit over 2 ohms when hot after 30 seconds of running.

Having said all of that, if you get 6-10 volts to coil + when the key is in RUN, the ballast is not your issue. If it was bad, the car would fire when cranking but not keep running when you released the key to RUN.

Edit to add: This applies to the low resistance side of the ballast. The high resistance side should be about 5 ohms.
 
AJ/FormS said:
As to the ballast, if it gets hot, with the key in run, it is working. It takes a few minutes. This is better than a resistance test, cuz it means something downstream is pulling a load through it. However the ohmeter should show less than 2 ohms, through either side, with it removed from the circuit.

nm9
He changed his story in post #7. Now it's electronic,and the pics in post#10 prove it.
And he still has not stated his problem.
Click to expand...
Ahah, all the work for nothing.....doh.
 
The problem AJ is I have no spark at the spark plug.
Not trying to be difficult, as I mentioned Imnot great with electrical.
 
ok so my meter when I touch the prongs together gets 2.0-2.5 ohms. top of ballast is 2.7 and bottom is 5.9

edit...I am going to go pick up another meter cause this one is giving conflicting readings. I have 37 ohms on top now...
 
Last edited:
krazykuda said:
ECU??? With points???

There is no ECU with points... Only electronic ignition... .
Click to expand...

Actually, "technically" you are incorrect. Some early electronic ignition was electronics switched by..........breaker points. In fact, Mopar had one for the old hemi cars. Not only that, but you CAN run a Mopar ECU off points!!!! Just stab a breaker point dist in there, and hook the dist. wire to the bare end of the two wire ECU connector. Yup. It will run.

The old Prestolite "Transignitor" is just one of them There were several others aftermarket, including the Tiger SST CD ignitions of the early 70's

CDI_TigerSST.jpg


transignitor.jpg
 
The thing you are doing with voltage checks.........

It is VERY important to understand what it is you are measuring and why.

For example, there are two ways to crank the engine..........by using the key, or by jumpering the starter relay. These two small differences create BIG differences at the coil during cranking

1....When cranking the engine "normally" using the key, the ignition switch sends FULL BATTERY voltage direct to the coil. This is the brown bypass circuit, "IGN2" which comes from the switch, to the coil+ side of the ballast. During cranking, you should have "whatever battery" voltage is, and certainly more than 10V

2....If, instead, you jumper the starter relay, the bypass contacts in the ignition switch are NOT active, and NOW you have the ..........reduced battery voltage due to the starter.........minus the additional drop through the ballast resistor to the coil. The coil will have MUCH less voltage

++++++++++++++++++++++++++++++++

SO!!!

A....Turn key to run, measure coil POS and NEG. Compare to actual battery voltage. This tells you a couple of things.......whether the coil is getting "normal" expected voltage from the battery, which varies due to the ballast, and ........also whether the coil is drawing current through the ECU. This could give you a clue as to whether there's a bad connection at a connector or whether the box is poorly grounded. Coil NEG should be quite low, down around 1 volt while getting say, 8-10V at the coil+

B.....Clip voltmeter to coil POS and crank the engine USING THE KEY. Now you are checking for the bypass circuit being active, and good connections in the harness. Here the battery should be above 10V during cranking, as well as the coil POS connection. If this is low, I would either fix this first, or work around it by........

C.....Clip an alligator clip lead to the coil + and run over to battery source. NOW you have full battery to the coil. Now see if you have spark. Don't leave this connected any longer than necessary to test.

+++++++++++++++++++++++++++++++++++++++

When testing for spark, FIRST eliminate ALL high tension wiring, including the COIL wire. Get yourself a spark tester from the parts store, and "rig" it from the coil tower to ground, where you can see it under the hood gap. I use a Lisle, less than 10 bucks

s-l300.jpg


A good working system should produce blue snappy sparks at least 3/8" and more typically 1/2" long

ONCE YOU get this far, THEN worry about the coil wire, the cap and rotor, and the plug wires and plugs

+++++++++++++++++++++++++++++++++++++

Along with everything else, I wrote up a pictorial test some time ago

Maybe this helps, and maybe not

Here's a post I made about the simplest way I know to get across testing the ECU/ ignition parts

74 duster electrical problems


You need a coil, the ECU and the distributor

Lay it out on the bench. Follow the diagram. Find the two distributor pickup terminals on the ECU. Hook them to the distributor

Hook the ECU case to battery NEG

Coil does NOT need grounded

Distributor does NOT need grounded.

Hook coil + to the power lead terminal on the ECU. Get a clip lead hooked there and let dangle. This is your battery "hot" when you are ready

Hook something from coil "case" to a probe for testing spark.

Hook up your power clip lead. Twist the distributor shaft while holding the test probe near the coil tower. The thing should make sparks

If not, unhook distributor. Take first one, then the other pickup clip leads, and "tap tap" ground them at the battery connection. Coil should make 1 spark each time you do so.

If not, try another coil. If that does not fix it replace the ECU

IF you hook it all up and it WORKS, then there is something AFU in the car harness. SUSPECT a bad ECU connector OR a bad DISTRIBUTOR connector
=============================================
This is all you need to test the basics of the ignition. You can easily test the ballast separate. A battery, the ECU, distributor and a coil, and of course some test leads

2ai0wsj.jpg


Below, the basic diagram for a 4 pin ECU

166lmj7.jpg


Below, the wire for testing spark. I use my 12V test light. No, LOL the spark won't blow up the bulb

166lmj7.jpg


Below, the ground connection. ALL you need is one wire from batt NEG to the ECU case

xawjl.jpg


Below, the two distributor connections. In the car these are polarity sensitive, but for testing does not matter

b3opvm.jpg


Below, the coil NEG connection

6jfywp.jpg


Below, battery PLUS connection, one wire to this terminal of ECU and jumpered over to + side of coil


11lqu5l.jpg


Below, all hooked up and ready to test (except for battery ground). Should produce sparks at least 3/8" and typically 1/2" long

1zzoya0.jpg


Below, distributor "one wire" test. I have removed the other distributor wire for simplicity. Take the bare connector end or this clip lead (the yellow) and with everything hooked up, ground it repeatedly. Each grounding should result in a spark (In this photo you need to hook up the ECU ground wire, I left it off for the photo)

vgitld.jpg











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