6 x 8, you continue to awe me with the breadth and depth of your knowledge, and my continuing appreciation all you have helped and taught me! I will go through you last post thoroughly for full understanding and learn more. That said, I should have responded earlier with your first post today that was in direct response to my last one yesterday. I know what the problem is and have halfway proven it. During the day today between other ‘life events’ I will put the time in to make sure everything is good, then post back with all the gory details.

My ‘ranting’ post last night had to do with my shaking my head at what I had done. Disgusted with myself, not disheartened but at the same time glad I figured it out even though it shouldn’t have happened in the first place. But ‘sall good!

“What A Long Strange Trip It’s Been” keeps going around in my head. Stay tuned…

 

Depth and breadth of knowledge ??

No, half of what was written was guesswork.

My Father used to say, ''Don't believe half the lies I tell you''. LOL

On a serious note, I'm glad I could help, I'm pleased that you learned a lot, and I'm pleased that others can learn from this thread, myself included.

Once again, YOU have determined where a problem lies.

I'm actually pleased that there have been multiple issues, as it accelerates the learning from it.

If you didn't have a problem, or if you had not made mistakes, you wouldn't have learned as much.

Don't be disgusted with yourself. Rather laugh at yourself for whatever it was that you did wrong.

I have a huge list of the things that I did wrong initially, and here's an example.

I fitted a Pertronix ignitor to my Motorcraft, and without ever firing up the engine, I destroyed it.

One week after fitting the replacement ignitor, I destroyed that too, albeit in a different manner. FFS !

Anyway, post back when it suits you, there's no rush, although I must admit the suspense is killing me with regard to your ''what I had done'', and hell yeah I'm staying tuned. LOL

 

With my last post I was feeling highly confident that I had identified the last hurdle to overcome for a smooth running and well-tuned engine. The entire time I was assembling the new HT leads I was bothered by how the terminals were supposed to make solid contact with the distributor posts. I soldiered on. And had a crap running engine until I finally figured out I used the terminals for a cap with the contacts on the outside (male); mine are inside (female). There goes a set of $70 leads…

So yesterday I used 6 of the new leads refitted with the correct terminals, together with 2 old Taylor leads until I could get a new set. It started right up. I warmed it up, set initial and ran a curve. BAM, right on cue, backfires starting at 1770 RPM up to 1900 +/-. When ported vac advance was connected it misfired at around 1600 RPM. It got progressively worse with throttle and had to be feathered to run, all the while the timing light was flashing erratic. Sigh…

Let’s recount the parts that have been replaced so far (and this is embarrassing): dizzy, cap, rotor, ignition module. What’s that leave? Why not spend another $40 and replace the coil even though the existing one ohms out within spec? That started me down another side path. What makes one coil different from any other? The parts store showed two basic ones for this engine: electronic ignition and breaker points. I don’t have points, but neither is this system “electronic”. It is “breakerless” in Ford’s terms. A 1974-only system that I’ve mentioned a few times in this long-winding thread. Anyway this fact tripped me up again when I selected the electronic ignition coil. When I got it home I found the + and - terminals were the clip-on type and I needed studs. The points-style coil had studs. A call to the parts store for the ohm specs of that coil was pointless (no pun intended): the young guy (aren’t they all anymore, lol) behind the counter didn’t have a clue. So this morning I trudged back to the parts store to pick up the new HT leads that had come in. I took the electronic coil with me together with a MM. I took ohm readings on the breaker-style coil and found them exactly the same as the electronic: 1.5 primary and 8850 secondary. The Ford service manual specs ranges of 1.0 - 2.0, and 7,000 - 13,000 respectively so I exchanged for it. I have a concern that has developed, however. This coil has “Use with external resistor” printed on it. I thought I had a resistance wire going to it but late today (after going through everything that I write beyond this), I found 12.2V at the wire when disconnected from the coil, and 6V when it’s connected. I think I might be on my way to burning out a new coil??

I installed the coil and replaced the two temp old Taylor leads with new Accel. Started right up, let it warm, checked initial which was 14*. Started there and ran a curve. Small(er) backfire at the same RPM as usual, 1770 / 27*. When vac adv was connected and then given throttle there was a rapid succession of backfires. Great…

So with all the backfiring that has been happening over a period of weeks now, I
pulled the plugs. No surprise, they were pretty black. This low compression smog era engine has a bit of blow by anyway. I cleaned them and confirmed .040 gap. Reinstalled, started and warmed. Initial was 17*, ran a curve, and … no backfires! I tried to get it to by running up slowly to and through the 1600 - 2100
RPM range, then down, then back up. Smooth. Cool, until vac adv is connected. At 1730 RPM and gradual throttle there is a series of backfires and the timing mark jumps way advanced at the same time. I can jump past the the trouble spot with hard throttle but it starts backfiring if the higher RPM’s are sustained without constantly working the throttle. I can alter the range the backfires start by adjusting the vac advance can.

Later I started the engine when it was semi-warm, with vac adv plugged. Under slow and gradual throttle I can “feel” a misfire in the 1,700 - 2,100 RPM range but no backfires. That’s progress I guess. But where from here?

So here I am with more questions than answers, again. To start, why am I getting two different voltage readings at the + coil wire (12.2 and 6V) when in Run depending on whether wire is disconnected or not? BTW, when actually started and running I saw 12V on that wire.

 

Fail !!!

Be at the janitor's office at 4pm on Friday for a 4 hour detention, and bring your own chalk.

You will write,''I must not be a lazy bastid'' on the blackboard 1,000 times.

Then, given the severity of your laziness, you must be back at the janitor's office at 8am on Saturday for another 4 hour detention, and once again, bring your own chalk.

This time you will write,''If I am lazy again, I must give 6 by 8 the Ranchero keys'' on the blackboard 1,000 times.

There is no window in his office, and there will be a stock take of the cleaning materials after you're done, so don't even think about stealing one of the two brooms.

Also, you will not be allowed a cell phone, and you will be given one glass of water, per session.

Why the harsh reprimand ?

''I apportioned this down to the inch and spot- measured probably 50% and eyed the remainder. I’m pretty confident mine are within spec.''

The underlined parts of the quote provide the answer to the question.

If it turns out that you are Steve Austin, a.k.a. The Six Million Dollar Man, who possesses a Bionic Eye, then I apologize profusely, withdraw the detentions, and would like your autograph !!

 

I just spoke to the janitor, and he said that the light is not working in his office.

I hope you're not afraid of the dark !! LMAO

Ok, back to being serious.

Ignition Power Supply

A 12v battery is in fact not 12v, it is 12.6v which is made up of 6 cells @ 2.1v per cell. (Measured when cold)

Your battery measured 12.6v when cold, so that's good.

When you turn your ignition key to 'on', power is basically running along a wire from the battery to the coil.

But, along the way the power meets resistance, at the key switch, at the module, thus reducing the voltage at the coil end.

Your 12.2v reading at that point isn't bad, and in the context of this thread, is not a problem.

At least now you know, with 100% certainty, that you do not have a resistor wire or ballast resistor in the ignition power supply circuit.

When an engine is running, the voltage is no longer 12.6v, but +/- 14.5v.

You can/should measure this next time the engine is running.

Assuming your battery reads 14.5v at this time, you should see +/- 14.1 at the coil.

You only saw 12v, so that needs to be looked into. We'll come back to this.

If you're curious, next time the battery is warm, let's say just after you've checked for +/- 14.5v, and the engine is off, check the battery voltage reading.

You'll see something like +/- 13.5v. This is due to the battery not having settled yet. (I forget what that's called.)

This is why batteries should always be measured cold when a faulty battery is suspected.

 

While investigating the misfire/backfire issues, only change one thing at a time.

I'm posting separate posts to deal with one thing at a time.

HT Leads

LOL at you fitting the wrong terminals.

Welcome to 'learning the hard way'. I can relate.

We know for a fact that your coil HT lead is faulty, and that the number 8 lead has an issue.

We also know that the coil worked prior to the dizzy removal and adjustment.

Fit the old coil, and all of the old leads .

Run the engine in the dark and observe the miniature electrical storm in the coil lead, and see if any other leads light up, especially the number 8 lead. (Did you not do this already ???)

This is the only time that you can physically see a faulty HT lead. (Unless you have a bionic eye. LOL)

Leave the old coil in place, and don't touch anything else, not even the spark plugs, or the rear wheel tire pressures. Nothing !

Next up, check 100%, not 50%, not probably 50%, but 100%, of the new leads that you plan to fit.

If they are within spec, and with the correct terminals fitted (LOL), replace the old ones with them.

Get a 'feel' of how the caps 'click', or whatever, onto the plugs and coil tips.

With only the leads replaced, run the engine again. Did this solve the problem ?

If there's still a backfire/misfire, observe the leads in the dark. Any visible problems ? (It doesn't hurt to check again even though they passed their ohm tests.)

 

Spark plugs

We were looking for coincidences, Go Seahawks! coincidences, and we found what looks like one, the number 8 lead.

But ! We also found a genuine coincidence, and that was the coil lead.

I ignored spark plugs until now.

Hmm, it wouldn't hurt to fit new ones. You never know.

Are they as old as the HT leads ? (Maybe that doesn't matter.)

The .040'' gap is a bit small. You could increase them to 0.45''.

While I remember something that I'd forgotten.

You had asked why the engine runs even with a zero continuity measured in the coil HT.

The conductor wire has worn out, broken down, gone a.w.o.l.

Imagine that wire is physically broken, and resembles stepping stones. (Say)

Low voltage cannot jump the gaps. (The gaps in between the stones.)

40,000v or whatever can jump the gaps, giving what looks like continuity, and thus allows the engine to run, but with a misfire.

Hope that makes sense.

 

Timing Curve

Once you have set and checked a timing curve, there should be no need to check the timing again, but you did, and maybe it's lucky that you did.

Assuming you did not touch the dizzy, which means the timing wasn't changed, it's interesting, hmm, annoying, that it moved from 14* to 17*. WTF !?

Not sure why the bloody thing changed, but the comments in the next 'coil post' might eventually shed some light.

 

The Coil

The coil, dizzy and ignition module have to be matched.

I can only explain that with what I know.

1/

I had an MSD coil paired with a Motorcraft dizzy, and the dizzy had a Pertronix ignitor 1.

The coil measured 0.7 ohms.

The ignitor 1 specified a minimum resistance of 1.5 ohms

I had to fit an 0.8 ohm ballast resistor into my standard non resisted wire. (0.7 + 0.8 = 1.5 minimum)

I can't remember where it was fitted, but it was fitted in accordance with the ignitor 1 wiring instructions.

2/

I threw the Motorcraft dizzy in the bin, kept the MSD coil, and fitted a Pertronix dizzy which came with an ignitor 2 fitted.

So, the MSD coil stayed at 0.7 ohms, but the ignitor 2 only required a minimum of 0.45 ohms.

Seeing as 0.7 ohms exceeded the 0.45 minimum, I threw away the ballast resistor.

I was left with only a dizzy and coil, and fresh new 12 gauge wire throughout the ignition circuit.

This was the only time that I measured the volts at the coil. The battery was something like 14.5v and the coil was something like 14.4v. Very close. Nice !

Leaving the resistor in place would not have damaged anything, but power would have been robbed from the engine. Exactly the sort of 'pep' that you are trying to achieve.




I assume that the ignitor module is equivalent to your stand alone control module.

You have a dizzy, a coil, and a module.

The dizzy can be points or electronic, but so can your module !!!

I don't know the answers to these questions, but what I know doesn't matter, YOU need to know.

Is your AUTOLINE D4006 a DS 1 or DS 2 equivalent ?

Does your module mate to a DS1 or DS 2 ?

Does your coil mate to a DS 1 or a DS 2 ?

Does the DS1 or DS 2 require a resistor in the circuit ?

I don't know why your coil measures 6v with the engine off, and only 12v running, but my first off the cuff response is that the coil is a 6v coil.

Maybe revisit Redroad and 440's earlier posts ?

 

And last but not least !

Electronic or breakerless ?

I am guessing that points is points (clever huh ? LOL) and that 'electronic' is the same as 'breakerless'.

(Points require a resistor)

Seeing as you have no points in the dizzy, I'd assume that both the coil and module should be electronic.

If your existing coil was in fact for points, I'd expect something to have been destroyed by now with the lack of a resistor, but I don't know for sure, and could easily be wrong.

If your existing coil is for electronic, but has different types of wire attachments, ok, that's probably just a visual cosmetic difference.

I'm probably wrong about the module being points or electronic too, but you need to be sure what's what.

LOL @ the pointless pun.

Now FFS make sure your next post doesn't exceed one sentence, otherwise there will be another detention. LOL

 

Ouch! But OK, I’ll take my lumps for taking a short cut especially when chasing an apparent gremlin. Lesson learned.

I read each of your most recent posts. Based on your last one I need to revisit the various incarnations during the evolution of Ford’s breakerless/electronic ignition systems. I’ve spent a fair amount of time researching them in various forums and blogs, as well as the Engine manual of the full set of 1974 Ford Car Shop Manuals I’ve had forever.

Short summary as I have learned:
- first effort into a system without points is known and called by Ford “breakerless”. This was offered only on select engines only in 1974. This is a black grommet box.
- in 1975 there were changes made to the module that had something to do with internal resistor, IIRC. This was DuraSpark, later to be known as DS1 when further updates and changes were made in later years which became known as DS2. Grommet colors indicate the type and/or if there is built-in retard at Start. I know I read one article in particular that laid it all out. I’ll see if I can find it.

In full disclosure I may be a little off on the exact specifics on the second bullet but it’s pretty close. The attached pics from the engine manual backs up the ‘breakerless’ designation and troubleshooting.

It shows there should be a resistor wire on the + side of the coil limiting voltage to between 6.6 and 4.5V.

Which gets me back to the coil. I’m having trouble developing an understanding of the difference between an electronic and breaker point can. I replaced an Accel 8140 with a Standard Ignition FD471, a breaker-type according to the description. It is for a resistor circuit though it is also listed as 12v. Standard Ignition FD476 which is listed for electronic has incorrect 12v and negative connectors. It does not specify an external resistor.

From all this it seems to me at this point I should run a new resistor wire but I’m not doing anything until I know more.

Much longer than one sentence but not worthy of detention. This time.

 

Yeah, fair enough, that wasn't a bad post at all.

And seeing as you said ''lesson learned'', Saturday's detention has been waived.

You have to face some sort of reprimand, so Friday's 4pm appointment still stands.

However, seeing as you are making an effort, the 4 hour detention has been cut down to 3 hours 55 minutes, and yes, I know I'm being generous. LOL

By the way, the janitor's name is Hank.

I'm sorry that I'm not being very helpful with your coil etc, but I'm more sorry that you are having to endure such pain.

OMG, breakerless then electronic , black, then green, then blue, then whatever color you would like. FFS !

Contact breakers, a.k.a. points, a.k.a. breaker points, are exactly that, breakers.

Therefore anything without points, a.k.a. breakerless, is electronic.

Apologies for my negativity, but I just don't like the nasty OE systems, whether they work or not.

Given my negative attitude, I didn't read your page photos in detail.

I did however google the Accel 8140, and saw 1.40 ohms as the primary resistance. That's a very useful number !!

FD471 and FD476 both stated to use resistor wire, one on the can, and one in the notes, as per summit's website. (Very f$$king unhelpful ! E.G. How many ohms in the resistor wire should one have?)

Can you find out the minimum ohms on the controller that you have ?

If it is 1.4 ohms, then that's why the Accel coil works with it, without a resistor wire.

If the coil was 0.7 ohms say, then you would need a resistance of 0.7 ohms minimum. Make sure you understand this so far.

So, without knowing the primary resistance of the FD471 and FD476, how would we know how to connect them ? (But you know how to measure that. )

In the meantime, I get the impression that it is safe for you to refit the accel coil and HT leads as discussed earlier.

At least then you can rule out the HT leads as being the problem or not after fitting new ones.

Not doing anything until you know more is a fair comment too.

 

I forgot to add :

Looking at the pictures in the pages you posted, I see that both the conventional (points) and breakerless systems have resistor wire in their circuits.

That kinda tells me that the minimum ohms on the coils in both setups are the same, and that both the points and amplifier module, require the same minimum ohms.(Or something like that)

Maybe that's for Duraspark 1's , and Duraspark 2 systems use different ohm rated coils and modules ????

I'm getting a Duraspark rash on my hands. Gotta go.

 

I lost it.

 

Yesterday I decided to take my licks and visit the janitor’s office for detention. This took away time to work much on the Ranchero but man, it was an interesting time! Hank recalled you well, 6 x 8, and told many stories of the exploits that landed you there. The one involving a chimpanzee and mannequin was especially hilarious!

I was still able to squeeze a little time under the hood. After fully warm I checked initial (it hadn’t moved; I saw you picked up on where it had on a previous occasion). I didn’t change anything and ran the engine up and down from idle to 2100 RPM or so, back down the then back up, slowly and quickly, doing everything I can to get a backfire. Nada. It still ‘feels’ a little rough in the troublesome 300 RPM range, or is it my imagination? Am I detecting roughness and engine vibration or is that natural? I guess time will tell.

Among other things you’ve discussed is electrically matching components, specifically resistance. I don’t know what the module is, the value isn’t published and I don’t know where to measure it. It should match unless defective since it’s supposed to be OEM equivalent. Same for the dizzy. The old Accel coil has 1.5 primary resistance. As I recall there was around 8000 secondary but I can’t verify. I had tossed it in the trash and am guessing that broke some windings because secondary readings are all over the board. I had previously measured and posted the resistance values of the Standard Ignition FD471 and 476. Both have primary of 1.4. I’m fitted with the 471 and secondary is 8760. The Ford manual calls for a range of 1.0 - 2.0 primary and 7000 - 13000 secondary.

I measured voltage at the coil with the engine running. I recorded readings with MM + on the coil + and the MM - on the engine block, then in the battery post. Same readings. Voltage jumps all over the place from 2V up to 12.2V. It never sits steady for more than a second or so. The same thing when I measure across the coil + and - terminals: the reading jumps all over the place from 2V to 5+, but seems to be mainly in the 4.8V - 5 range. WTH?? Shouldn’t this be zero?

While on the topic of coils, I contacted Standard Ignition via email through their website asking for technical specs of their FD471 and 476 coils, as well as the resistance that is supposed to be on the positive wire. I haven’t heard back.

My next planned steps are to first put in a fresh set of plugs and see what that does. If there are still any running issues I’ll pull the HT leads and confirm with certainty they are all within ohm spec. Then onward to figure out how and why the voltage at the coil is so erratic. Is it somehow related to having 12.2V on the wire
that is supposed to be resisted? And BTW, how does a resistor wire lose it’s resistance? Rhetorical but genuine questions I need to find answers to.

FYI, I have never observed the engine running in the dark with the old wires. They were pulled and laying on the floor when you first suggested doing so and I didn’t reinstall them. I don’t feel compelled to do so now just to see arcing unless I’m missing another reason to do that.

Hope your case of DS rash isn’t getting worse. I hear a couple of whiskey shots can help. Now, go visit Hank. He’s lonely and misses your company!