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Discussion Starter #1
Yes...I know fallacy and fiction are basically the same. But I think it follows with the issue I am about to raise.

The DURASPARK II is a know good retrofit to non electronic igntion cars, such as my 70 XR7 and 73 Mustang. I don't use it personally, but many do.

There are dozens of posts indicating the DURASPARK II module is capable of retarding the ignition timing of a distributor during engine start up. Some statements such as this are posted on this site. In fact, this feature alone is often cited as the reason some use DURASPARK instead of the bowtie conceived HEI ignition.

However, based on my knowledge of the ignition system and the mechanical timing features, I am unable to see any way for the DII to change the timing of a distributor.

From my vantage point, the timing of a distributor is changed through 2 basic ways:

1. Rotate distributor, which is basically rotating the distributor cap but leaving the gear inside alone.

2. Rotate the distributor plate, which is done via vacuum or centrifugal advance.

Since the module has no control over either of these methods, how could it possibly change the timing?

Thank you for enlightening me.
 

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The retard is accomplished electronically inside the module. When starting, the white wire to the module gets a voltage signal that causes the module to delay firing the coil.
 

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:tup:

What he said (during CRANK)...

And this is the DURASPARK II with the BLUE strain relief.

There is also a DURASPARK II IGN MODULE with YELLOW strain relief that receives a signal from an outside mechanical sensor. The retard feature (while running) is for altitude and/or pre-igntion.
 

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These guys are on it. ZGW (welcome to the forums!), to take this one step further, this is an early electronic design, where simple delay of the trigger signal causes a retard of the output spark. 10 years later, they ditched all the mechanical timing guts, and used an expanded 'retard' system, commonly called "next-cylinder" mode. What this means is that the trigger of the previous cylinder is actually used to calculate when to fire the next cylinder. Instead of retard, if you delay it long enough, you're actually firing the next cylinder in advance.

This is the basis of all modern ECM-controlled distributor schemes. If you instead take the trigger signal from the crank and calculate the next cylinder firing, you don't even need a distributor - you now have distributorless operation simply firing multiple coil packs in the correct firing order.

David
 

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get a box from a 79-81 mustang/capri turbo... it has a 2 step retard, IIRC, 4 degrees, then an additional 2, depending how you hook up the pressure switches...
 

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Discussion Starter #6
Actually, if you read the service manual page it says:

"On SOME applications a SPECIAL Duraspark II module is used...with 3 connectors instead of 2." Further reading of the text and figures show the necessity of the Distributor Modulation Valve which adjust the timing mechanically via the vacuum advance.

Only a Duraspark II with this 3rd connector and the Distributor Modulation Valve(DMV) has the capability to advance/retard the ignition.

As a result, it is false to believe any Duraspark II module alone can provide for advance/retard. The Duraspark II requires a 3rd plug and the DMV.

Thank you for the great service manual page!!!
 

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... Only a Duraspark II with this 3rd connector and the Distributor Modulation Valve(DMV) has the capability to advance/retard the ignition.

As a result, it is false to believe any Duraspark II module alone can provide for advance/retard. The Duraspark II requires a 3rd plug and the DMV.
You are mis-reading it without further info. Only DSII has altitude-compensating spark retard with the 3rd connector and sensors. That is not saying none have retard but those. I and thousands of others have proven working spark retard on various DS modules, where the spark retard is usually intended for cranking - not just altitude compensation or turbo boost. But, you can retard any time you want. All you have to do is apply power to the white wire and watch your timing. Bingo. Retard.

David
 

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You are mis-reading it without further info. Only DSII has altitude-compensating spark retard with the 3rd connector and sensors. That is not saying none have retard but those. I and thousands of others have proven working spark retard on various DS modules, where the spark retard is usually intended for cranking - not just altitude compensation or turbo boost. But, you can retard any time you want. All you have to do is apply power to the white wire and watch your timing. Bingo. Retard.

David
David is spot on.

I am one of the many that used the common 2 plug blue grommet controller's retard feature with great success when I rewired the Mustang when it had higher compression. It is a great feature.

I used this schematic that specifically lists the white wires function and the use of the blue grommet:

Duraspark conversion

Nothing proves it like actually doing it . . . . . .
 

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You can also use it as an advance device... just run it normally with both retard steps engaged, then remove each one if you want... A good app for this would be to have it retarded for startup cranking, and once the engine fires, restore the advance.....
 

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You are mis-reading it without further info. Only DSII has altitude-compensating spark retard with the 3rd connector and sensors. That is not saying none have retard but those. I and thousands of others have proven working spark retard on various DS modules, where the spark retard is usually intended for cranking - not just altitude compensation or turbo boost. But, you can retard any time you want. All you have to do is apply power to the white wire and watch your timing. Bingo. Retard.

David
Seems I screwed up when I mentioned the YELLOW IGN MOD (casual conversation and obscure factoids should be avoided at all costs).

Dave is quite right (as usual). The White Wire retards IGN ADV @ crank for less load on the starter motor. Many (for whatever reason) do not wire that circuit in with a conversion.
 

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You can also use it as an advance device... just run it normally with both retard steps engaged, then remove each one if you want... A good app for this would be to have it retarded for startup cranking, and once the engine fires, restore the advance.....
"A good app" doesnt that do it for the oem set up .

or did you mean switch to crank mode for high load retard
 

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"A good app" doesnt that do it for the oem set up .

or did you mean switch to crank mode for high load retard

that's what i was suggesting, with a high initial advance, you could set it up so the engine will start when hot under these conditions, and when it catches, restore advance. You could wire the step activation through an oil pressure switch or something..

Overall, I was trying to get people to think outside the box. (no pun intended)
 

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that's what i was suggesting, with a high initial advance, you could set it up so the engine will start when hot under these conditions, and when it catches, restore advance. You could wire the step activation through an oil pressure switch or something..

Overall, I was trying to get people to think outside the box. (no pun intended)
That's what Dan was saying - the most common use of the retard function is exactly what you are suggesting. The factory would connect the white wire to the starter relay (fender solenoid), so when you cranked, the DS would retard, and once the engine caught, releasing the key would restore advance. This is what Dennis described he did on his application in an earlier post. Simple start retard.

For creative uses, another is with non-vac-advance units, where retard is active all the time (and the engine timed so it's 'normal' with retard active), then the retard deactivated at cruise to give increased MPG with effective advance. I've seen this done with one throttle switch and a Hobbs switch.

Another popular creative use was during the early '80s with that "new" stuff - nitrous. The white wire was simply attached to the nitrous solenoid, so when triggered it would retard the ignition. This was a welcome simple solution to large HP shots that otherwise required involved techniques to provide the necessary retard for high horsepower with high cylinder pressure.

The same technique was used with superchargers and turbos for retard with pump gas before the 'turbo' version of the DS came out. Without a retard function, you were stuck with either ridiculously low compression or high-octane fuel.

BTW - if using DS, unless there is need for some other function, I strongly recommend the red-grommet box (California/non-Federal) over the others as it is considerably more powerful. While not commonly used in decades past due to extremely high cost and low availability; the red boxes are now common and cheap. The red box has dwell control, uses no coil ballast resistor, and so allows the use of HEI-style coils with higher spark energy and much wider gaps (or higher compression) and better firing of polluted (rough idle) and lean-burn cruise mixtures.

David
 

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Thanks for the interesting discussion. I just converted to Duraspark II with a blue grommet module, Motorcraft part number DY-893 (1U2Z-12A199-A). The conversion works great, idle is smooth, etc. However, the reason I did it was to obtain the start retard functionality presumably offered by the white wire, and I'm not sure this is happening.

I have noticed that with the engine running, I can connect the white wire directly to 12V and NOTHING happens. While running, the timing does not change regardless of whether the white wire is energized or not. Others have reported seeing the timing instantly change when doing this, and that's what I'm hoping to achieve also.

Is there some reason why the module would be smart enough to only retard when actually starting? Or was the start retard feature removed from this newest (1U2Z-A) version of the module? Did I get a bad module?

I am very confident that everything is wired properly. Any thoughts about what I can do to get the start retard working?

Thanks!

[UPDATE: Got it working! See newer post 03-13-2013]
 

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Odd. I haven't used a real Ford box in a long time (just cheap aftermarket ones), and it is possible there is an RPM cutoff feature now - but I wouldn't assume so. To verify if it's either non-functional or has RPM cutoff, watch your timing with a light while cranking and apply power to the white wire. If it's limited, you should see the timing jump back. Otherwise it's not working, and there is no reason I know of that the feature designed for it it should have been removed.

I don't have any blue-grommet boxes here to test for readings on the white wire. If your cranking test fails, perhaps someone else can test for readings to see if they show different than yours.

David
 

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Thanks David. Great idea! I will disconnect the coil from the cap to keep the engine from firing, and observe the timing while cranking -- with and without the white wire connected. That should answer the question. If it isn't retarding, I'll be chucking this module and trying a different one. I REALLY want the start retard feature!

I also have a yellow grommet box with the third connector. My understanding is that the 3rd connector connects to various sensors (altitude, temperature, etc.) which can cause timing to retard. Does anyone know how to wire to this third connector? Or, if the sensors are ON/OFF in nature or have a continuous range whereby the amount of retard can vary based on sensor output?
 

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I would leave the coil connected to the cap so you can read the #1 wire. Disconnect your plug wires instead and ground them. Alternatively, a common "quick check" method is to pump the carb several times to flood the engine so it won't start right away. That may give you enough cranking time to test. Just let it rest after testing for a while and it will start normally.

I don't recall about the yellow box. I'd have to do some re-re-search on it.

David
 

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Oops, that was a dumb idea on my part. Kinda hard to get a timing light to fire with the coil disconnected from the cap! Do you think it would be okay to simply disconnect all spark plug wires without grounding them?
 

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... Do you think it would be okay to simply disconnect all spark plug wires without grounding them?
I will say "probably". While the oil-filled coils of old were much more resistant to internal arcing, newer versions and almost all production coils in the last 20 years are epoxy-filled. Unfortunately, it seems the spark finds it's way through epoxy easier (especially after some aging and internal micro-cracking). This means newer cars with high-energy ignition should never have a plug wire disconnected while running, as coil failure is much more likely.

So, having done CYA with all that, I'll say you'll be fine for cranking tests if you have an old-style oil-filled coil. If not - ground 'em.

David
 

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THE IGNITION RETARD IS *NOT* a fallacy. It is now a confirmed FACT! After some experimentation and head-scratching, I was able to get the ignition retard to work. In the process, I discovered some information that the community might find helpful. It actually was a wiring problem, but one others may likely encounter as well.

I was using the Painless 30812 wiring harness as-delivered, and connected it according to the wiring diagram in their manual. I NOW BELIEVE THE PAINLESS 30812 WIRING DIAGRAM IS INCORRECT. It will allow the engine to run, however it defeats the ignition retard feature.

The 80312 harness has white and brown shorted together in the harness, and both are connected to the I terminal on the solenoid. At first thought, this makes sense. While cranking, the I terminal becomes energized and provides full battery voltage to both the coil via the brown (ballast resistor bypass) wire, and to cranking indicator input of the ignition module via the white wire. All well and good, except that when NOT cranking, the brown wire still has voltage on it because connects to the positive coil terminal. Because white is shorted to brown in the harness, this same positive coil voltage therefore appears at the white ignition module input. On most cars, including mine, this voltage will be less than 12V due to drop across the ballast resistor. Regardless, this voltage is high enough to cause the module to believe the engine is cranking all the time. Using their wiring diagram, touching the white wire on and off of a 12V source has no effect because you are then just bouncing the module input between two voltages that are both above the threshold used to activate the retard feature.

In other words, if you wire the Painless 30812 harness the way they tell you to, your ignition module will be in retard mode 100% of the time and you will not enjoy the start retard feature. I have just notified them about this design error; perhaps they will make revisions. In any case, the harness still has value if you apply the following solution:

1) Snip the brown wire thereby disconnecting it from the white. Tape off the ignition module side of your cut; it is no longer needed. Then connect the other, ignition coil, side to the I terminal of the solenoid, thereby re-enabling it to function properly as a resistor bypass during cranking. (Note: some cars, including mine, already have an I-terminal connection with a resistor bypass wire in the factory wiring. In such case, the brown Painless wire is not needed at all, but it must still be cut and disconnected from white -- snip it and tape off both sides of the cut.)

2) Connect the Painless white wire NOT to the I terminal as they suggest, but rather to the S terminal. The S terminal only has voltage while actually cranking. As explained above, the I terminal will have voltage all the time while running, if a resistor bypass wire exists (and it should).

Once I made these mods, the system began working like a dream. With the engine running, I was able to see the timing change in real time by energizing and de-energizing the white wire. On my 1U2Z-AA blue-grommet module I measured the retard to be a consistent RPM-independent, 5 degrees. I'd say that's just about ideal. Now I will be able to run more initial advance and enjoy the improved performance, while still actually being able to restart the engine when hot.

I hope someone else finds this info helpful.

Tim
 
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