Spark, sometimes.
 

86 F-250, 460, 4 speed, 4x4, carb., Duraspark ignition system. Sometimes I have spark, sometimes I don't. I check it at the top of the distributor at the coil wire. What I know about ignition systems is not much. Any suggestions will be appreciated. Best, CB

i am having similar problem. will be listening in

Most of the time it happens after sitting over night. It won't have spark until I leave the hood open and have the automatic trickle charger on it for a few hours. I know this is strange. I'm wondering if it doesn't have enough power to run the electronics when the starter is turning. Mechanically, I can do anything to this vehicle. When it comes to electronics, I is dumb. Best, CB

C.B.

A follow-on to ctubutis' post.
The red wire provides power in start and a signal to the DSII to retard the timing while starting.
The white wire provides power while running.

My personal thinking (maybe way off base) on your situation is that you might have an issue with the pickup in your distributor.
Perhaps IT has a bad ground, or a chafed wire.
if the Orange or Purple wire is frayed and shorting to ground, signal won't trigger the DSII box to spark.
If you have dew or condensation in the morning maybe leaving the hood open to charge the battery is allowing these wires going to, or inside the dizzy to dry out and the system goes back to working as it should.
At the least I would unplug all the harness connections, clean up the pins and apply some dielectric silicone to keep the connections free from oxidation and moisture.

Just my two cents, and no guarantee that it will help, but it is something to look at.

JimsRebel,

I know the DS2 grounds inside the distributor. I'm saying that if the reluctor pickup wire's insulation is compromised moisture could ground it. The trigger signal is not strong.

I, also, am going to ck into all that, Jim and Jim. I am making progress. I found an unconnected ground...so I now have good current into the cab. No ign yet, however.

First thing I'd do is have the Duraspark-II module tested. These can be tested at most auto part stores.

A failing DS-II module can have these symptoms you describe.

The quick connect, connectors are supposed to be packed with white lithium grease at both the module and the distributor connectors.

On Truck side of the harness, and orignal Motorcraft Modules... The wire colors are as follows...

Red/Light Blue stripe: Start circut.
White/Light Blue Hash: Run circut.
Red/Light Green stripe: Coil Wire Hot. (7 volts aproximate in Run, 12 volts aprox. in Start mode, with starter disconnected)
Light Green/Yellow stripe: Tach (Coil ground signal to DS-II module and Tach in dash)
Black: Ignition Ground
Purple: Stator
Orange: Stator

On Aftermarket And Replacement Motorcraft Modules the Red and white wires are reversed...

Red: Run
White: Start

All other colors are the same as above.

Thanks. I'll report when I check it out. Best, CB