I have a Duraspark distributor for my 360, and a green grommet Duraspark module. Everything checks out, but I want to make sure I have a reliable system. Is the DS I system fairly reliable, and what would the advantages be to going to a DSII blue grommet box? If I do go the DSII route, can I use the same distributor or is there a difference on that?

 

I was under the impression that the grommet color only has to do with some timing differences due to emissions. There is one difference between Duraspark systems that I am aware of and that is one system keeps power to the coil any time the key is on, and one keeps power to the coil only when the engine is turning I think? I can't really remember. I don't know if that is between I and II or II and III. I've also been told that Duraspark I was just breakerless ignition without a module. Hopefully someone else will have more info; I'm just throwing out every little piece that I can remember. I bet NumberDummy will have some good info on that.

 

So basically, if I use my complete DS I system, I'll be set?
Has anybody run a full 12v through a DS I with a TFI coil? I have run a DSII box like that with acceptable results, but don't know about the whole current sensing part of the DS I.
As far as just hooking it up, is the old resistor wire for the points acceptable, or do I need a different resistor? I haven't been able to find a definite answer to that in any of the other threads mentioning DS I.

 

I have only had TFI on one vehicle before and can't answer much on that.

The Duraspark module is pretty standard across the board. It's a simple discrete circuit. It's only job is to trigger based off of the Hall effect sensor in the distributor, and break the ground to the coil when this signal is sensed. A separate cranking signal (white wire) adds some delay between these two events when the starter is cranking, to retard timing and therefore ease wear on the starter. Those are the only two things the module does. All Duraspark modules sense when the armature on the distributor shaft lines up with the pickup coil (Hall effect sensor) using the same signal therefore everything is compatible.

To answer your earlier question, you should be able to use mix and match your Duraspark modules without problems, provided the two modules have the same "pin-out". You might as well hook it up and try it out. There isn't a clear difference between the grommet colors but I am under the understanding that it has to do with emissions purposes. For example, the Duraspark module has the ability to add delay between when it senses the armature lining up with the pickup coil (analogous to breaker points opening) and when it actually fires the coil. This delay is adjustable. It has been shown that retarding timing can reduce emissions, therefore different modules can have different effects on the timing. I do know that there were some changes over the years involving when the coil is powered, and some modules had an extra signal. The blue grommet module is the most common. I do not know if the blue grommet module is more reliable than a green grommet module, or if a green grommet module has any known reliability issues. NumberDummy might have some information on module differences.

The following link from Autozone has some decent information on Duraspark history over the years, it is inline with my knowledge of the system's evolution. It shows that additional functionality was added over the years, but the module's main function remains unchanged - which is to control the amount of time between the armature lining up with the pickup coil and the coil firing.

http://www.autozone.com/az/cds/en_us...rInfoPages.htm

For the coil, you need to drop the 12V down to 7-9V for both points or Duraspark. Therefore you can take the resistor wire setup from a points system and use it for a Duraspark system; it will be fine. Hook it up, turn the key to run (don't start the engine) and check the voltage between the positive coil terminal and ground to make sure you're in the 7-9V range with your setup.

 

I think the Ds1 were wired diffrent. I have a 74 F100 360 with the brown gromet ans tried to install a DS2 with the blue gromet and it wouldent start.
I cant remember where but I foun a wireing diag. for both and they were wired diffrent.
Leadmic

 

Brown grommet is a California emissions module if I remember correctly, and is a "horse of a different color" from everything I have read or been told.

 

Leadmic is exactly right, the DSI modules from '74 and '75 (the brown and green grommet modules) are 7 wire modules, ford deleted the 7th (blue) wire in '76 with the DSII (blue grommet) modules, the DSII 6 wire modules are not interchangable with the earlier DSI 7 wire modules.

 

That is interesting to know, thanks for the information. Do you know what the blue wire is for? If I had to guess, I'd think it would have to do with leaving the coil connected when the engine isn't turning since that's the major change between the two systems. Sorry for any confusion.

 

I'm not sure what the blue wire did, i only found all this out through trial and error, when my DSI module bit the dust i went to the parts store and bought a module for a 1975, bring it home, hook it up and no crank, thinking i got a bum module i go get a replacement, same thing, no crank, it's just a simple module but being stumped as to what could be wrong i look in the box for any "instructions" and i find a slip of paper stating "Ford deleted the blue wire but it will still work with my DS ignition" but needless to say from first hand experience and that of a few others this is not correct, i checked every parts store in town specifically asking for either a 74 or 75 DSI module and they were all 6 wire modules and included that "deletion" note in the box, so apparently this is a snafu on Fords part, i eventually found a NOS module on ebay two months later for 10 bucks, this problem most likely isn't encounterd by too many guys as the DSI was only around for two years in 74 and 75, when guys with pre 74 points upgrade to electronic they go with DSII, and most guys with DSI upgrade to DSII eventually so i doubt it's a well known problem.