Sparking problem

[Bristol ave fag]

All basic stuff. these vehicles do not use a ballast resisted feed. They are for points and condensers.

Electronic ignition systems, whether factory Mopar or aftermarket, don't utilize breaker points, thereby not actually needing a ballast resistor to control amperage through the pickup coil. ... Quite simply, if your distributor has breaker points the answer is yes; if not, the answer is no

[Penelope Stopit]

Bristol ave fag said:

All basic stuff. these vehicles do not use a ballast resisted feed. They are for points and condensers.

Electronic ignition systems, whether factory Mopar or aftermarket, don't utilize breaker points, thereby not actually needing a ballast resistor to control amperage through the pickup coil. ... Quite simply, if your distributor has breaker points the answer is yes; if not, the answer is no

Thank you very much for this

Saved for posterity

[adam quantrill]

Now we have finished swinging the handbags about maybe we could address Bigfish's ignition problem?

So far we have 3 cars measured with similar low supply voltage measured at the coil, that are running fine, and the Bigfish car, which has a similar low voltage, but not running. So I propose moving on for now and measuring some other parameters, to help the OP. As a reminder this is what I'm interested in:

a) voltage between coil + supply and battery + (coil -ve earthed)?
b) voltage between coil - supply and engine block during cranking?
c) voltage between coil - supply and battery - during cranking?
d) battery voltage when cranking?
e) voltage between battery - and engine block while cranking?
f) battery voltage with headlamps on [typical = 12.0V]?
g) Spark quality (or does it run) when the coil + is taken direct to battery +?
The last two are mainly to confirm the "low voltage" effect:
h) Disconnect battery - and then battery +.. Ignition on. Measure resistance between battery + clamp and ignition coil primary +.
i) Measure coil primary resistance (ignition off).

[Bristol ave fag]

adam quantrill said:

Now we have finished swinging the handbags about maybe we could address Bigfish's ignition problem?

So far we have 3 cars measured with similar low supply voltage measured at the coil, that are running fine, and the Bigfish car, which has a similar low voltage, but not running. So I propose moving on for now and measuring some other parameters, to help the OP. As a reminder this is what I'm interested in:

a) voltage between coil + supply and battery + (coil -ve earthed)?
b) voltage between coil - supply and engine block during cranking?
c) voltage between coil - supply and battery - during cranking?
d) battery voltage when cranking?
e) voltage between battery - and engine block while cranking?
f) battery voltage with headlamps on [typical = 12.0V]?
g) Spark quality (or does it run) when the coil + is taken direct to battery +?
The last two are mainly to confirm the "low voltage" effect:
h) Disconnect battery - and then battery +.. Ignition on. Measure resistance between battery + clamp and ignition coil primary +.
i) Measure coil primary resistance (ignition off).

With this sort of low ht problem you would firstly, ordinarily suspect the amplifier that's what pulls the primary down to earth.... 5amps down to earth and remember this 1 amplifier and 1 coil have to do this 8 times every 720 degrees. Having said that the op says the amp has been changed. So i asked him to check the wire from the amp up to the coil for high resistance in the loom but he has not got back to us yet..

[Penelope Stopit]

Bigfish_74

Hoping all is well

[KKson]

Now now. Let's all be nice........ hope everyone supporting our Wedge community stays safe and is well. Strange times.......

[Penelope Stopit]

This topic was highly entertaining for a short period of time

Never witnessed so much nonesense being posted over and over again

The entertainment value died a quick death once the proof was posted yet ignored

Hoping that Bigfish_74 is ok

As mentioned above, these are strange times and may account for some strange postings withing the PH forums, stress is a terrible thing

[O mage]

Penelope Stopit said:

This topic was highly entertaining for a short period of time

Never witnessed so much nonesense being posted over and over again

The entertainment value died a quick death once the proof was posted yet ignored

Hoping that Bigfish_74 is ok

As mentioned above, these are strange times and may account for some strange postings withing the PH forums, stress is a terrible thing

I would agree strange times
You just seem to want an argument even when proved wrong in practice you will not accept the results you seem to enjoy giving people the wrong advise.The nonsense is coming from you.

[Penelope Stopit]

O mage said:

Penelope Stopit said:

This topic was highly entertaining for a short period of time

Never witnessed so much nonesense being posted over and over again

The entertainment value died a quick death once the proof was posted yet ignored

Hoping that Bigfish_74 is ok

As mentioned above, these are strange times and may account for some strange postings withing the PH forums, stress is a terrible thing

I would agree strange times
You just seem to want an argument even when proved wrong in practice you will not accept the results you seem to enjoy giving people the wrong advise.The nonsense is coming from you.

There is not a word of truth in your above post

For you to post the above comment is extremely childish and naughty to say the least

What I've posted in this topic is common knowledge and can be found in many reputable automotive electrical website's

You remind me of another poster here that used to stalk me until I blocked his posts, I wouldn't know if he still continues to stalk me as I can no longer see his posts

Your username is now being added to my Greasemonkey blocked list

Bye bye, you made a poor effort in attempting to cause trouble without reason

[O mage]

What has been observed by Bigfish_74 has also been observed by KKson on his car and is quite normal for these vehicles check as many as you like and they will all drop across the coil.. Its all in the thread....

[adam quantrill]

Mine too! A whopping 6V across the coil. On a working car.

[Penelope Stopit]

adam quantrill said:

Mine too! A whopping 6V across the coil. On a working car.

6 Volt across the coil ? Taking it that you're earthing the coil negative before measuring across the coil

If the above is the case

Your vehicle is either wired with a ballast resistor in series with the ignition coil supply, has a faulty or incorrect coil fitted or has a massive volt drop

A vehicle with a massive volt drop will run if fitted with a 6 volt or 9 volt coil

Fractions of a volt less than battery voltage should be found at the coil positive when there is no ballast resistor in the circuit

This information is of common knowledge, it is nothing new and is fact

[O mage]

adam quantrill said:

Mine too! A whopping 6V across the coil. On a working car.

Yes that's good quite normal then. you will see a better picture of whats happening in the circuit when the primary is pulled down as its running with an oscilloscope on the trigger side.

[adam quantrill]

Ha ha be careful with that last time I had a scope on an ignition coil primary the back EMF fried the front end. I would recommend using some clamping diodes.

[Penelope Stopit]

adam quantrill said:

Mine too! A whopping 6V across the coil. On a working car.

Trust that you will have the decency to post back here explaining to all as to why there is only a 6 volts supply at your cars ignition positive terminal

Sharing is caring

Remember, with ignition on, a fraction of a volt less than the then measured battery voltage should be present at the coil positive terminal

If a ballast resistor is wired into the coil supply, calculations are needed to determine that the correct resistor and ignition coil combination are being used

Lies and more lies have been posted to this topic and it would be very sad if anybody was to read them as being anything other

Without mentioning a username

A reputable electrical engineer has posted the facts in this topic that verify the expected voltage supply at the coil positive when no ballast resistor is present

[adam quantrill]

So measure (h) then:

a) voltage between coil + supply and battery + (coil -ve earthed)?
b) voltage between coil - supply and engine block during cranking?
c) voltage between coil - supply and battery - during cranking?
d) battery voltage when cranking?
e) voltage between battery - and engine block while cranking?
f) battery voltage with headlamps on [typical = 12.0V]?
g) Spark quality (or does it run) when the coil + is taken direct to battery +?
The last two are mainly to confirm the "low voltage" effect:
h) Disconnect battery - and then battery +.. Ignition on. Measure resistance between battery + clamp and ignition coil primary +.
i) Measure coil primary resistance (ignition off).

[O mage]

Can i suggest dipping your coil in a jug of water, when doing these tests not only to stop it overheating but then you could add a tea bag to it whilst you ponder where the voltage is going at least then you will have a lovely cup of tea a the end of the day.

[blitzracing]

A strobe is not a reliable way of measuring your HT. The strobe picks up the sharp drop in HT voltage as the plug tip fires, so you need the voltage rise to take place before the plug ionises and then arcs to get the spike. You wont see this if your plugs are sooted up as the HT never rises as its voltage leaks away through the carbon, so check the plugs for soot or fouling.

A simple HT test that will show if the coil primary (and primary voltage ) and secondary is OK is to simply remove the king lead from the distributor cap, and then tape the end 1 CM from the chassis and crank the motor and see if it gets a spark, this represents 30KV in dry air that would show all is well. Just don't hold on to it !! This will eliminate all the arguments about primary voltages if it works.

Just in case anyone is trying to measure DC voltages across a coil with a meter on a running engine, don't do it, the wave forms are full of back emf spikes and its not a fixed DC level anyway, so you wont get any sense. All tests need to be static. Penelope is talking lots of sense here unlike some people.

[Penelope Stopit]

blitzracing said:

A strobe is not a reliable way of measuring your HT. The strobe picks up the sharp drop in HT voltage as the plug tip fires, so you need the voltage rise to take place before the plug ionises and then arcs to get the spike. You wont see this if your plugs are sooted up as the HT never rises as its voltage leaks away through the carbon, so check the plugs for soot or fouling.

A simple HT test that will show if the coil primary (and primary voltage ) and secondary is OK is to simply remove the king lead from the distributor cap, and then tape the end 1 CM from the chassis and crank the motor and see if it gets a spark, this represents 30KV in dry air that would show all is well. Just don't hold on to it !! This will eliminate all the arguments about primary voltages if it works.

Just in case anyone is trying to measure DC voltages across a coil with a meter on a running engine, don't do it, the wave forms are full of back emf spikes and its not a fixed DC level anyway, so you wont get any sense. All tests need to be static. Penelope is talking lots of sense here unlike some people.

Got a feeling there were some having a laugh in the worst possible way, liking the 30KV 1 Cm gap test

[O mage]

These vehicles have not got ballast resistors fitted in the ignition circuit not one of them as they are all 12v coils .Same case for chims, griffs ,seacs anything fitted with this type of ignition. Some people would rather make things up than admit they are wrong.