Duraspark II conversion no spark

[BigMeatyClaws]

Hello all,

I come to you again with a request for aid. 1985 2.8 ranger with a duraspark conversion wired exactly per the guide.
Using an in-line spark tester, I have no spark starting at the coil to distributor. I have 12.5 v going to coil from module in run and 10.5 in start. I have a wire going from the starter relay "I" to the coil in addition because I thought it might need full voltage at start. I have tested the pickup in the distributor which checks out. I've also tried swapping ignition modules with no change. I've checked all of my harness for continuity and it checks out. Battery at full charge and tested. New battery terminal wires and a ground strap.

I kept the original coil from before the conversion because it was less than 2 months old. Could this be my issue? Any other ideas?

 

[RonD]

You can test the coil by having 12v at its positive connection and then connect and disconnect the negative terminal, should get a spark out each time negative is disconnected

That's what any spark system does
In the old days the Points connected and disconnected the negative terminal on the coil
Electronic ignitions do exactly the same thing but use a "sensor" to detect rotation of distributor shaft to "time" the connection and disconnection of coil's negative terminal

So if the coil can be sparked manually, but spark module is not grounding and ungrounding the coil's negative then either sensor is not working, timing pulse, or module has an issue

You can put a 12v test light on battery positive and the modules wire to coil negative, light should pulse when engine/distributor is turning

And that's another thing that can happen.................is the distributor turning?
Have you seen the rotor turning with cap off?
I have chased my tail a few times with busted distributors, lol, "of course it turning", "oops"

 

[RobbieD]

Another thing to check on a Duraspark conversion is that the adapter ring and cap are properly lined up and locked down onto the distributor. That can prevent the rotor from contacting the cap's button and/or misaligns the rotor to the plug wire contacts.

 

[BigMeatyClaws]

You can test the coil by having 12v at its positive connection and then connect and disconnect the negative terminal, should get a spark out each time negative is disconnected

That's what any spark system does
In the old days the Points connected and disconnected the negative terminal on the coil
Electronic ignitions do exactly the same thing but use a "sensor" to detect rotation of distributor shaft to "time" the connection and disconnection of coil's negative terminal

So if the coil can be sparked manually, but spark module is not grounding and ungrounding the coil's negative then either sensor is not working, timing pulse, or module has an issue

You can put a 12v test light on battery positive and the modules wire to coil negative, light should pulse when engine/distributor is turning

And that's another thing that can happen.................is the distributor turning?
Have you seen the rotor turning with cap off?
I have chased my tail a few times with busted distributors, lol, "of course it turning", "oops"

The distributor is turning. I'll check out the other stuff and report back.

 

[BigMeatyClaws]

Another thing to check on a Duraspark conversion is that the adapter ring and cap are properly lined up and locked down onto the distributor. That can prevent the rotor from contacting the cap's button and/or misaligns the rotor to the plug wire contacts.

Adapter ring? I just went with a cap that was for a 79 pinto and it attaches to the distributor. The cap doesn't have any wiggle or anything.

 

[ford4wd08]

Adapter ring? I just went with a cap that was for a 79 pinto and it attaches to the distributor. The cap doesn't have any wiggle or anything.

Did you go with the Ford Duraspark Module, or the GM HEI module?

The '85 has some funky wiring that goes along with it (prepping for Fuel Injection the next model year I'm sure).

I went with the HEI on my 85 as you didn't have to alter to factory wiring, you just had to splice to both side of the coil and run it to the HEI module. The rest came from the distributor or ground.

Then you could just cut out all the computer harness from the main harness.

Here is some reference info I had.

1985 Bronco 2 Duraspark Distributor with HEI Conversion

Hi all, I am going to convert my 85 2.8L to the duraspark distributor with the GM HEI set up. I'm just making this thread for reference and to have part numbers handy. The distributor I will most likely go with this one...

www.therangerstation.com

 

[BigMeatyClaws]

I went with the duraspark module. I followed the guide on here. I'm thinking about getting a gm module and rewiring the whole thing

 

[RonD]

The GM HEI is a way more reliable setup AND less expensive, and those two things don't go together very often, lol

 

[BigMeatyClaws]

Ok, update. I tried removing the neg from the coil, no light. I know at the plug to the coil it is receiving 12 v. Before this issue the truck ran until a bad alternator slowly drained the battery. When I got the new alternator, fully charged battery, etc., this no-spark issue arose. I checked under the distributor cap, all appears well. Screws were tightened. It looks like the rotor is touching the point on the cap it's supposed to, as evidenced by the circular wear mark on the rotor. So is it possibly the duraspark module?

 

[BigMeatyClaws]

You can test the coil by having 12v at its positive connection and then connect and disconnect the negative terminal, should get a spark out each time negative is disconnected

That's what any spark system does
In the old days the Points connected and disconnected the negative terminal on the coil
Electronic ignitions do exactly the same thing but use a "sensor" to detect rotation of distributor shaft to "time" the connection and disconnection of coil's negative terminal

So if the coil can be sparked manually, but spark module is not grounding and ungrounding the coil's negative then either sensor is not working, timing pulse, or module has an issue

You can put a 12v test light on battery positive and the modules wire to coil negative, light should pulse when engine/distributor is turning

And that's another thing that can happen.................is the distributor turning?
Have you seen the rotor turning with cap off?
I have chased my tail a few times with busted distributors, lol, "of course it turning", "oops"

Ok, correction to my last post, my spark tester did have a slight light when I grounded the coil negative on the engine block. So could that be something with the distributor? With the module? Is there another test I can do to check?

 

[RonD]

What kind of spark tester are you using?

You would use any tester on the coil to distributor wire, and it needs a path to ground or spark has no where to go, so put a spark plug on the end of that wire who's tip is touch engine metal

Ignition Coil sparks when you REMOVE the ground wire from coil, when coil has 12v and ground it does nothing, it's "powered up"
When you remove the ground(or 12v) that's when it releases the high voltage spark from the Secondary circuit
Then you ground it to "power it up" again

That's what Points did and now-a-days what "spark modules" do

 

[BigMeatyClaws]

What kind of spark tester are you using?

You would use any tester on the coil to distributor wire, and it needs a path to ground or spark has no where to go, so put a spark plug on the end of that wire who's tip is touch engine metal

Ignition Coil sparks when you REMOVE the ground wire from coil, when coil has 12v and ground it does nothing, it's "powered up"
When you remove the ground(or 12v) that's when it releases the high voltage spark from the Secondary circuit
Then you ground it to "power it up" again

That's what Points did and now-a-days what "spark modules" do

I'm using an in-line type so a light bulb between plugs to the coil wire and then to the coil. I tried to use an ohmmeter to test at the distributor between the two non-ground wires but I couldn't get a reading as it jumped all over the place.

 

[RonD]

Say your spark tester is on #1 spark plug wire, unplug that wire from distributor and plug it into the coil directly
Then ground and unground the coil, key on(12v to coil)

 

[BigMeatyClaws]

Say your spark tester is on #1 spark plug wire, unplug that wire from distributor and plug it into the coil directly
Then ground and unground the coil, key on(12v to coil)

I will do that tomorrow and report back. Any idea what's up with the ohmmeter thing I mentioned? Is that a sign of pick-up failure?

 

[RonD]

OHM testing for TFI module here: https://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml
Module is disconnected from distributor to test the 3 "sensor" connectors

The Hall effect sensor(pickup) inside distributor needs to be test when TFI module is unplugged, these rarely fail but its possible
Loosen distributor but MARK where it is, you will need to turn the distributor
The Hall effect sensor detects a permanent magnet mounted next to it, there is a wheel with "vanes" attached to distributor shaft, it rotates the "vanes" so they pass between the Hall Effect sensor and the magnet
When a "vane" passes between it cuts the magnetic field, when there is no "vane" so open, magnetic field is back
The 12volt Hall effect sensor Pulses 12v on then 12v off, as the wheel spins
12v and ground should test as under 100ohms, its just a coil of wire
signal wire to either 12v(or ground) should show high then low ohms as you turn distributor so vane cuts off magnet then "window" restores magnetic field