• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Anyone have really bad luck with Duraspark ignition modules new from the store?

berickso

Newbie
Joined
Jun 29, 2015
Messages
16
So, the Bronco died on me in an adjacent neighborhood. It's stalled like this before, but normally will fire right back up. This time, not so much.

The Bronco has a 302 from an 81 F-150, Painless harness with Painless Duraspark harness. Most of the electrical is from NAPA.

It loses spark suddenly, like the engine has been turned off. This has led me to buy a bunch of ignition switches from NAPA, and that usually fixes the problem. This time it didn't work. I replaced the pickup coil in the distributor, the ballast resistor, the ignition switch, the coil, etc., and it would spark at start up but then die when it moved from "start" to "run." I even put on an old starter solenoid I had, just in case somehow that was causing the gremlin.

I keep a spare ignition module, and I swapped that out, but nothing happened. This afternoon in frustration, I went back to NAPA and bought the two ignition modules they had. I put the nicer "Echlin" module on, it fired right up, then died about a minute later. Got it to fire again, it worked for another minute or so, and then died. I put the cheaper NAPA "proformer" unit on and it fired right up, allowing me to get it in the garage. I wasn't going to push my luck after that.

Have gone through the wire loom, don't see any obvious problems. I checked the NSS just in case that could cause it, but it too is adjusted correctly and the wires are solidly connected.

Is it just these things are this bad, or could there be something wrong with the truck that is cooking them? The last one lasted for about three months, I think, and when it started to die, I was convinced I had carb problems (which is also entirely possible).

Anyone have a better option for where to get the blue grommet modules? Or do I just keep scouring junkyards for an OEM Motorcraft?

Thanks,
Brian
 

SHX669

Bronco Guru
Joined
Jan 9, 2009
Messages
1,997
I think we use different terminology but I think the culprit is what you're calling the " pickup coil in the distributor " . I bought " their best" and mine would barely run off and on . I checked the timing and it had changed and the " pickup coil " was only firing intermittently.
Oh - what coil did you replace the old one with ? with the ballast resistor you don't want to use an internally resisted coil . This combo drops too much voltage .
 

armynavy17

Contributor
Full Member
Joined
Jan 9, 2010
Messages
361
I've always heard the only modules worth anything are original motorcraft. They're becoming rare enough that I always take a look any time I'm in a junk yard.
I think I have the original duraspark troubleshooting manual somewhere, I'll take a look and post it if I do.
 

SHX669

Bronco Guru
Joined
Jan 9, 2009
Messages
1,997
Davis Unified Ignition used to have good modules and reman distributors with a longer upper shaft bushing.
 
OP
OP
B

berickso

Newbie
Joined
Jun 29, 2015
Messages
16
My coil is the Echlin (NAPA) IC21. It doesn't say on the coil whether or not it's internally resisted. My understanding was that the DSII system needs an external resistor to protect the module, is that incorrect?
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
The resistor is only on the coil’s Red w/green positive wire. Usually no resistor for the ignition module. And never (that I know of) for a blue grommet model.

Unfortunately it’s very possible to get multiple bad parts right out of the box these days. So everything you just replaced is still suspect.

Easy to check the distributor pickup coil / stator. Measure ohms at the connector between the orange and purple wires. Should fall between 400 and 700 ohms. With slight variations depending on which book you read. But that’s the most common value I’ve seen.
 

billh1289

Contributor
Full Member
Joined
Jul 2, 2006
Messages
471
Loc.
Jackson, NJ
Rock auto carries a blue grommet module they list as a Motorcraft. Has anyone had any luck with that one?
 

m_m70

Contributor
Sr. Member
Joined
Jun 14, 2001
Messages
1,459
Loc.
Pacifica, CA
Rock auto carries a blue grommet module they list as a Motorcraft. Has anyone had any luck with that one?
Haven't tried the rock auto modules but I got this one from amazon that has motorcraft in the casting and no probs in the last couple years. I bought two and they both work so I have a working spare.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
I second check the ohms on the mag pick-up and this part it is very wise to buy motorcraft it is a very sensitive and precision part. make sure your ignition module case is properly grounded.
 

AC932

Contributor
Full Member
Joined
Sep 17, 2018
Messages
247
In addition to the pickup coil resistance, check the air gap between it and the armature (there's probably a spec for it somewhere, but they should be pretty close together). The rivets on mine loosened up and caused the pickup to contact the armature, throwing timing way off and spraying plastic chunks everywhere. You also shouldn't have much "wobble" where the pickup coil plate is attached to the distributor.

I had problems like SHX when I tried NAPA pickup coils. The truck wouldn't start unless I moved base timing to 23 degrees. They also wobbled around and were spaced out pretty far from the armature, which led to timing varying by about +/-3 degrees while running.

A Motorcraft NOS pickup solved my problem. I got mine from https://nospartsltd.com/.

I've been running a NAPA ignition module with no issues for 8 years FWIW.
 

nvrstuk

Contributor
Just a Bronco driver for over 50 yrs!
Joined
Jul 31, 2001
Messages
8,604
To answer the original question? Seems like ANY Duraspark replacement box is pretty much worthless.

GO OE, GO Motorcraft only. Even if it's a used unit from a boneyard that's 50 yrs old. Better than an Orielly's or Napa brand.
 

tirewater

Contributor
Sr. Member
Joined
Jan 28, 2011
Messages
1,040
Loc.
San Francisco Bay Area
Is it just these things are this bad, or could there be something wrong with the truck that is cooking them? The last one lasted for about three months, I think, and when it started to die, I was convinced I had carb problems (which is also entirely possible).

I'm thinking there's something wrong with your truck. Everything related has been replaced, including the wiring harness, the odds are perhaps higher than normal that something went awry along the way.

Given your symptoms, it sounds like a ground issue, or loose connection. The 'spark at start up but then die when it moved from "start" to "run.' quote brings two ideas. One is that the ignition switch or connector is not working properly. If that's fine, then the system is designed to deliver 12v to the coil on start via the 'I' terminal on the starter relay/solenoid. Have you tested the voltage at the coil?

There are so many variables here, especially with the aftermarket wiring harness, that I think it's best to start with the DSII pdf posted above and start working through it. It's an excellent resource.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,345
I replaced the pickup coil in the distributor, the ballast resistor, the ignition switch, the coil, etc., and it would spark at start up but then die when it moved from "start" to "run."
You say you replaced the resistor. Is that an external one mounted somewhere under the hood? The kind with the white ceramic base and the coiled spring-like conductor?

I even put on an old starter solenoid I had, just in case somehow that was causing the gremlin.
Normally a starter relay will not be able to kill a running engine. It's possible, if something really odd goes on internally, but it's very rare I'm thinking.
But if ever in question, you simply remove the small Brown wire from the "I" post of the relay/solenoid and that completely isolates it from the ignition system. Saves you from replacing the whole part.
And starter relays are probably the #1 most reviled member of the "bad-right-out-of-the-box" parts groups these days. So don't throw away any of your old ones.
In fact, words to live by these days are just don't throw away any of the old parts unless you confirmed they're bad.

Have gone through the wire loom, don't see any obvious problems. I checked the NSS just in case that could cause it, but it too is adjusted correctly and the wires are solidly connected.
In our case, an NSS is in no way related to the ignition system, so can't possibly kill a running engine. It can only keep an engine from cranking with the starter.

Is it just these things are this bad, or could there be something wrong with the truck that is cooking them?
Definitely either one. It's unfortunately all too common for people to get two, three, or even five or six bad parts in a row. Some have even had to go to other stores to see if their supply of parts was any better.
The culprits include Ford starter relays, ignition switches, ignition wire pigtails, Dura Spark ignition modules, etc. If it's electro-mechanical, name your part here and it's likely suffered the same fate at some point.

The last one lasted for about three months, I think, and when it started to die, I was convinced I had carb problems (which is also entirely possible).
Yep, you got it. Anything is possible, but with it cutting off instantly like you describe, my money is still on electrical rather than fuel.
You just never know sometimes. But that's why it's good to have a tachometer to watch too. If you're driving along and the tach needle comes to a stop before you come to a stop on the side of the road, then the issue is ignition related.
Of course, the downside to that is that sometimes it's the tach causing the problems!

Anyone have a better option for where to get the blue grommet modules? Or do I just keep scouring junkyards for an OEM Motorcraft?
That's still the preferred way. But at some point we'd like to think we can buy something brand new and have it work.
Keep your eyes open for Ford stuff and give it a try.

My coil is the Echlin (NAPA) IC21. It doesn't say on the coil whether or not it's internally resisted. My understanding was that the DSII system needs an external resistor to protect the module, is that incorrect?
Yes, sort of. The resistor is for the coil's positive power supply, but reducing the voltage to the coil probably does serve to help the modules last longer for having less current pulled through them. But primarily it's for the coil and the module does not use a resistor in it's power source wires.
Do you have a resistor on the ignition module as well as the coil?
I did not look up the coil's part number to see if it needs a resistor, but will when I get the chance. In the meantime, if it's listed as a "stock' replacement, then you have to assume it needs a resistor in line.

Paul
 
Top