Dead AGAIN!!! AHHG..

[Canadian1968]

The Car was running great the last 8 times I took it out.

I was out for about  a 20 min drive.  About 2 turns from my house I slow down for a stop and as I am doing so, the car dies. I coast over to the side, and try to start no go.

Get the car home, I have no spark.

Reading an article from Mopar Muscle about testing the pick-up coil.  I test the leads from the distributor getting 336 Ohms,  ok thats fine.  I then try cranking the engine,  apparently I should be able to get a AC of 1V at least .6 at the very least is neeed to trigger the ECU apparently.  ANyway I tried it twice and I could get not get a reading.

I pulled the distrutor out of the car, pulled it all apart with plans to buy a new Pick up coil.  Once I figured out how to take it all apart I threw it back together again to bench test it just for fun.  With the multimeter hooked up and spining the distributor by hand, I am now some how gettting a reading of anywhere from .4 to 1.2 V depening how fast I spin it. The slower , the less I get. I know how fast it turns during crank ( had the cap off when doing test on the car) and if I try to imitate the speed it hard to get a reading .

I am confused does my pick up coil sound like itis acting up ??

before people ask, I have 2 ECU's - 2 Coils- 2 reisitors which I all tried before looking at my pick up.

[A383Wing]

do you have 12v power to the resistor & "+" side of coil when key is on? Also check when it's cranking too.

[Cooter]

Does it wait till it gets HOT to die???
Are you running that damn Mopar Perf. junk? 'Orange/Gold/chrome" box???

If so, I had the same problem with about 5 "ECU" boxes I kept in the car. NONE would start it up. Swapped to MSD and never looked back.

[A383Wing]

if you are getting an "AC" voltage signal when spinning the dist on the bench, you just proved the pick-up coil works

[Canadian1968]

Yes I am using the MP distributor and orange ECU.
Yes the problem always comes up after the vehicle has been warmed up.  This time I cannot seem to get it started again. The previous times I only needed to let it cool down and it would start again for me.

I will try putting everything back in again and see if I can still get my readings I guess

[Cooter]

Sounds like a sh*tty ECU to me.

[b5blue]

Check that the bulkhead connections are clean and in good shape and get an aftermarket ecu as a test mule part to try.

[ottawamerc]

Rip it ALL out and put in a firecore RTR and then go driving and enjoy the hobby stop messing with old tech stuff summers too short for that

Scott

[Dino]

Check that the bulkhead connections are clean and in good shape and get an aftermarket ecu as a test mule part to try.

YES!  Last year when my car died it turned out to be a loose connection in the bulkhead.  Pull the bulkhead connectors, clean them and put a generous dab of dielectric grease on them before you reconnect.

[69rtse4spd]

Don't know if this helps or not but last year in the 70, went to town to have lunch with the wife. Got there just fine, later got back in to leave, nothing. Long store short, the air gap in the pick up some how opened up to wide. Everything was tight,  , replaced the dist. no more problems.

[Canadian1968]

I took the ECU out of the car, took it to work and hooked it up to the boss's 67 GTX ( exact same setup ).  It fired the car, so that proves that the ECU is ok.

Now I was trying to bench test Coil, by simply hooking up the + right to to the battery and then dragging the negavie across the bolt of the exhaust manifold, to see if I could get a spark from the coil.  I can get a tiny spark to jump from the end of the coil wire.  But during the test I get big spark from the negative lead  I am dragging on the bolt a the same time.. Should I not be getting my large spark from the coil wire itself??

[A383Wing]

sounds like coil went out

[Canadian1968]

What is normal resistance for a plug wire. I just tested the coil wire I am getting 7.5 (20K) = 7500 ohms.   And for the life of me I can't seem to get a continuity check from the ends of the wire. But I can get a resistance??

[Canadian1968]

Still trying to figure this out. 

When I turn my key to the run position my ammeter shows almost a -20 draw.  When I disconnect the ignition coil, this draw goes away, is that normal??   I tested the coil,  by raking the negavie lead across exhaust bolt, and watching the spark jump the end of coil wire.

Could my coil still be bad even though it passes this test???

I had the distributor tested by a local shop as well , the pick up coil is working fine.

[bakerhillpins]

69 in the garage with the silver box is showing less than -10 (how accurate is it??) with key in run and no lights on (dome, parking, exterior).

[firefighter3931]

Excessive resistance in the ignition wires will place an increased demand on the components. 

At 7500 ohms you're at least 7400 ohms over what i would consider acceptable on a coilwire 



Ron

[Canadian1968]

LOL,

Sorry but the draw is there if evem there is no spark wire connected. I agree 7500ohms is to much , but I odn't think its my no spark problem

Nothing is on, other than my dash , obvioulsy the gauges are powered up in RUN position. As said the draw is dropped as soon as the coil is disconnected

[firefighter3931]

I'll bet that the coil is shorted internally 

Have you tested the coil ?


Ron

[Canadian1968]

yes , as explained 2 post earlier

[A383Wing]

yes , as explained 2 post earlier

did you test it when it was hot? that's when they usually break down & fail...then when they cool, they will work again

[Cooter]

Just FYI here, but I have replaced my Coil [MSD first, then another MSD, then I bought an accel, then fourth one is back to MSD], FOUR times in the last two years.


I think even what was considered to be the "Good sh*t" is now "Cheap, Japanese Junk" as my pop used to say...

[Canadian1968]

I can't believe that every part for these cars seems to be "JUNK" these days, at least the electrical parts that is !!  Is quality control really that bad now? 

Geez really does not give me ANY confidence to drive the car ANYWHERE , it might just die cause of a crappy part?? BAH!!!


I ask around and people are telling me they have the exact setup on their car for 14 -5- 10 years. I can't seem to get one to work for more than 2 months

I guess the coil is to blame even though it acutally passed the test

[A383Wing]

pick up coils have been known to go bad when warm as well. Are you running a ballast resistor? If so, what is the OHM reading of it?

[firefighter3931]

yes , as explained 2 post earlier

You need to run a primary and secondary resistance test. That will tell you what shape the coil is in  


Ron

[Canadian1968]

I must have been looking at the wrong model for the coil. I just looked it up again and it said primary .325 ohms and secondary 7500 ohms .

My test gave me .9 ohms and 10500 more than double the primary. I took it back and will get a new one on monday

[Canadian1968]

I have 3 different  ballast to use  1.4 ohms , 1.0 , and .8 which would be the best to use . I was running the .8 before I had my problem . This was giving me 9.8v while running to the coil

[Cooter]

I can't believe that every part for these cars seems to be "JUNK" these days, at least the electrical parts that is !!  Is quality control really that bad now?  

Geez really does not give me ANY confidence to drive the car ANYWHERE , it might just die cause of a crappy part?? BAH!!!

This is not to say you have something before the coil causing it to "Burn out", but I know I didn't, they just "burnt out".
Nahh, you just need to keep spare everything in your trunk like many of us here do, and drive it anywhere you like.

[A383Wing]

I have 3 different  ballast to use  1.4 ohms , 1.0 , and .8 which would be the best to use . I was running the .8 before I had my problem . This was giving me 9.8v while running to the coil

sounds about right...9-10v at "+" side of coil is good...this is providing you are nit running a coil that is "internally resisted" like Ford used to do

[ACUDANUT]

IMO Chrysler's ECU's are still hard to beat.  That's all I run on my cars. No problems and no points. 

[A383Wing]

IMO Chrysler's ECU's are still hard to beat.  That's all I run on my cars. No problems and no points. 

yea...me too

[john108]

Dumb Question:  On the coil, there are 2 studs to attach wires and the high voltage cable that goes to the distributor.  Which connections form the primary and secondary circuits?  I think the 2 studs are the primary and the high voltage connection to one of the studs is the secondary, but which one?  Would it be negative, ground?

[A383Wing]

there is a "+" & "-" stud on coil. 12v key on goes to the "+" stud. Dist lead goes to "-" stud....middle high voltage wire on coil goes to center cap tower on dist cap

[john108]

Thank you
If I understand correctly:  The + and - terminals on the coil form the primary coil circuit from the 12v source and grounded through the distributor ( points or equivalent).  The secondary circuit consists of the center high voltage connection, of the coil,  which feeds the center of the distributor which feeds and grounded through each spark plug, as the distributor rotates.

[A383Wing]

yes

[Canadian1968]

I got a new coil and threw it on. No go. I started testing different points of the ignition circuit. I even pulled out and switched out the ignition switch with another one that I had.  My wife came out , and I got her to the turn the key,  while I checked the coil wire for spark. BAM I got strong spark as soon as she turn the key.

Ok Hook the wire up and the car fires, with the turn of the distributor to get timing back in check, the car runs like a champ again. Ok what changed???

I a put on another coil I had, and the car starts fine. I put on another ECU ( acutally the one that was on when the car died) and it starts fine.  Ok so it really doesn't seem to be any of the acutal components.

So I re due some of the previous voltage checks I was doing before.  I am now gettting a lot more voltage threw my brown wire ( ballast ) in START. Reading 10.8V thats 3 more volts then what I was gettting before.!!  WHY?? The RUN postions there is not near as much change in the test, closer to .5 V difference.

Is the problem in the start circuit?? But why did it die in mid cruise, when the key is obviously in RUN ??

I don't know how to track the problme now. The car starts and runs fine agian?? How do I make it fail. 

I don't knwo if it has any connection to my problem. BUT everytime the car has died on me, it has been as I am slowing down and putting on the brake???

This is obviously not your regular electrical problem!!

 

[ACUDANUT]

I have not read everything, but have you checked you starter relay under the hood ?

[Canadian1968]

I have not check the relay. But how would that kill me in mid cruise? The car always cranks fine. How would I test?

[ACUDANUT]

No, that not it then.  I thought it was a start up issue. Sorry.

[ws23rt]

In all this swapping around of parts have you tried a different rotor?
I had a similar problem once where sometimes the spark from the coil wire would short through the center of the rotor.
There was a microscopic crack in the rotor under the tang out of sight. It would work sometimes usually when checking things but would stop the car kinda like what you are experiencing 

[Canadian1968]

In all this swapping around of parts have you tried a different rotor?
I had a similar problem once where sometimes the spark from the coil wire would short through the center of the rotor.
There was a microscopic crack in the rotor under the tang out of sight. It would work sometimes usually when checking things but would stop the car kinda like what you are experiencing 

There is some " tracing" on the top of the rotor I noticed awhile ago,  but again that this would not prevent spark from coil itself.

Something WAS preventing the singnal from being sent to the coil OR my voltage was to low  to power either the coil or the ECU

[ws23rt]

So it runs fine now and the question is why?

[kokxville]

Rip it ALL out and put in a firecore RTR and then go driving and enjoy the hobby stop messing with old tech stuff summers too short for that

Scott

Couldn't agree more 

[Canadian1968]

So it runs fine now and the question is why?

Exactly , I pretty much just got spark all of a sudden. Parts that I was testing with before are working fine now. As I said the only thing I can say really changed is some of my voltage readings!?

[ws23rt]

So it runs fine now and the question is why?

Exactly , I pretty much just got spark all of a sudden. Parts that I was testing with before are working fine now. As I said the only thing I can say really changed is some of my voltage readings!?

I have had stuff like this happen several times in the past and sometimes the answer never comes back up.
In the future you now have more tools in your box to draw from.

A friend once called me to help with a problem that had him up a tree with frustration for days.  Since I had a clear mind about the whole thing I started with the basics. I twisted the + battery connection and from then on we were unable to locate any trouble. I felt bad for him and did not push it.
Another memory is a friend gave me a 57 Imperial. Complete running car because it had a bad electrical problem and he had spent enough on parts.
The generator drive belt was slipping.

[firefighter3931]

So it runs fine now and the question is why?

Exactly , I pretty much just got spark all of a sudden. Parts that I was testing with before are working fine now. As I said the only thing I can say really changed is some of my voltage readings!?

Have a close look at your bulkhead connections. I bet you have a loose connector or wire somewhere in this area based on the intermittent voltage readings and sudden loss of power.

Ron

[flyinlow]

My FSM shows resistance for a Chrysler coil  at 1.5 ohms +/_ 10% primary and 9400-10700 secondary.

What kind of secondary wires do you have? Stock coil/sparkplug wire have higher resistance. 5000 -20000 ohms is normal, depending on length.  Aftermarket magnetic suppression or solid core wires are much lower.


When you test the coil on the bench powering the positive side and making and braking the ground side you need to have a capacitor in the circuit just like the points and condenser distributor uses. Otherwise the primary will arc to ground as the secondary field collapses.

[Canadian1968]

My FSM shows resistance for a Chrysler coil  at 1.5 ohms +/_ 10% primary and 9400-10700 secondary.

What kind of secondary wires do you have? Stock coil/sparkplug wire have higher resistance. 5000 -20000 ohms is normal, depending on length.  Aftermarket magnetic suppression or solid core wires are much lower.

You have tried 2 coils and 2 ECU's and it still quits hot? When it quits have you verified there is no spark?

I tired 2 coils and 2 ECU after it died yes . Neither of them would give me spark. A couple days of testing and swapping things out , and I suddenly have my spark again. Now no matter what Coil, ECU, or even ignition switch the car runs fine.

NOW....... I was just out there testing my connections over and over. Everything is pretty rock solid as far as I can tell.  I decided to start the car and let it run for a bit.  Put my meter on the battery post I am charging at 13.3-13.6 V If I increse the RPM the charge does not change.  I put meter on the positive side of the coil get 9.4V at idle, I give the car a little RPM and my readings climb all the way up to 11.5 V!!! I throw the meter on the Blue wire up at the bulkhead thas giving me around 12.5 when I give a bit of RPM its around 13.1V  So basically any time I cam cruising around I feeding the coil almost 12V,  and my ECU is seeing 13V.   That doesn't seem right to me !??  I even saw my readings BLIP down to 6 volts for just as second as I brought the  RPMs up.

Why I am seeing all this change in voltage when back at my battery post its steady at 13.7 at max. ?

[Canadian1968]

The site doesn't seem to want to let me upload picutres for some reason.

But here is an old thread that with the digram of how I have the New Alternator and voltage regulator hooked up.

http://www.dodgecharger.com/forum/index.php/topic,96075.msg1107526.html#msg1107526

[flyinlow]

Sorry, skipped over the post about the ignition switch.

The short answer to the varying voltage is that I think that is normal. You are measuring voltage on a pulsating DC circuit at different pulsation (rpm) rates.

[flyinlow]

My 73 FSM (stock electronic ignition) shows current thru the primary engine off at 3.0 amps. Engine idling at 1.9 amps.

In a series DC circuit current flow is equal at all points. Voltage drop across the combined loads will  equal system voltage.  So you leave the battery + terminal at 13.7V (alternator running) you will use a very small amount of voltage getting thru the wiring getting to the ballast resistor , after pushing the current thru the ballast and additional wiring you are down to 9.7 V at the coil + terminal. The coil primary winding offers additional resistance and uses more of what's left. Next the current has to go to ECU where the circuit is opened and closed at the correct time to produce the spark in the secondary windings of the coil. Current returns to the battery where it's voltage is 0.0 V.  It would be a simple algebraic relationship between the resistor value of the components except that the coil is an inductive device and not a simple resistive device. Its value changes with frequency changes. So the coils percentage of the totals circuits resistance changes with rpm  ,which changes the voltage at the coil...... I think.  

[Canadian1968]

That made my head hurt!! Hahah

I understand why it's down to 9.5v at the coil that's what I want . I am asking is 11.5 v not to much for the coil consistant at cruise? I might as well have it hooked right to the battery??

[flyinlow]

I checked the "70 which has the single ballast resistor Mopar EE. MSD Blaster coil. Came with the car.

At idle - system 13.4v , Coil 6.9V

2500rpm- system 14.4v , Coil  10.1v

You said you had 3 ballasts, running the highest resistance one should reduce the voltage at the coil.

I don't live in fear driving around in 40 year old car.  I carry a spare cap, rotor, coil wire, long sparkplug wire (headers), ballast resistor and a spare ECU from my '73.

On the '73 which has a MSD box I carry a spare cap, rotor, coil wire, plug wire (headers) and an old points/condenser distributor. They are getting dusty.

After market ignitions have some advantages , but when your MSD, Firecore or whatever box quits 300 miles from home Sunday afternoon good luck getting parts quickly.

[Canadian1968]

Hmm ok, so you are getting increased voltage at the coil.  The current resistor is .8 I will throw in the 1.4 that will help keep the volts down. Thank you!

[Canadian1968]

I tried the 1.5 Ohm resistor. This gave me 4.6V @ Idle and 9V at @ approx 2500 . I didn't like the low 4.6 so I tried a 1 ohm resistor.
Now I am getting 8.6V @ idle and 10.8 @ 2500 rpm.  I think that is a happy medium

I found it interesting that the coil seem to be running fine off only 4.6V

Everything seems pretty good now, I am reading only .2 of voltage drop from the positive post of the battery to my blue wire on the ballast while running. That makes me feel pretty confident that all my connections are good and solid.

[flyinlow]

Sounds like a good choice . 

I found it interesting that the coil seem to be running fine off only 4.6V

Running fine warmed up with no load on the engine, yes.  Cold start or WOT where the coil needs to work harder to fire the plugs might be a different story.