No Spark Ignition Issue (1986 B2 2.9)

[E.B.N.S]

My first post on the forum so sorry if I forget to include something. I recently traded for a Bronco 2 and completely redone the fuel system (new tank, pumps, and filter).
Now that I know I have fuel I have to get spark. When I got the car the ignition timing was 180 degrees out so I fixed that and I have 12 volts and a spark at the coil i tested spark plug #1 and I get one spark when I turn the engine over but no sparks after that. Any advice would be appreciated

 

[tw205]

Do you get spark from the coil?

 

[E.B.N.S]

Do you get spark from the coil?

yes I get spark from the coil

 

[tw205]

yes I get spark from the coil

Is it just once like #1 plug or does it continue sparking. It’s easy to test the coil with a multimeter.

 

[RonD]

Welcome to TRS

Does the coil still have 12volts(well 10volts) when cranking the engine over?

Ignition switch has two 12v wires, one for RUN(on) and one for START, so the 12v can be shut off with key in START position
This is a hold over from the days coils needed a ballast resistor or resistor wire

 

[E.B.N.S]

Is it just once like #1 plug or does it continue sparking. It’s easy to test the coil with a multimeter.

I'll have to see whenever i have free time again. ill let you know

 

[RonD]

Any ignition coil sparks once when power is cut, that's how they work

With key on coil gets 12v and is grounded by TFI module
This powers up the Primary coil which creates a magnetic field around the Secondary coil, and this creates a Charge in Secondary coil
When 12v or ground is removed/cut, the magnetic field collapses allowing the Secondary's Charge to be released.........a spark

In normal operation the TFI module cuts the Ground on the coil, then re-grounds it to build up another Charge, based on rotation of distributor shaft(is distributor shaft rotating, have a look?)

So just one spark means coil was powered up once, but then not again
TFIs normal state is to ground the coil, un-grounding is its active state, momentary

The 12volts should be at the coil with key on always

 

[E.B.N.S]

Any ignition coil sparks once when power is cut, that's how they work

With key on coil gets 12v and is grounded by TFI module
This powers up the Primary coil which creates a magnetic field around the Secondary coil, and this creates a Charge in Secondary coil
When 12v or ground is removed/cut, the magnetic field collapses allowing the Secondary's Charge to be released.........a spark

In normal operation the TFI module cuts the Ground on the coil, then re-grounds it to build up another Charge, based on rotation of distributor shaft(is distributor shaft rotating, have a look?)

So just one spark means coil was powered up once, but then not again
TFIs normal state is to ground the coil, un-grounding is its active state, momentary

The 12volts should be at the coil with key on always

the coil only sparks once and it doesn't spark again

 

[RonD]

Coil needs to have 12volts all the time with key on and when cranking the engine, easy to test that

The TFI Module controls the coil's ground(-) terminal and thats what makes multiple sparks come from the coil, - wire pulsing on(grounded) and off(ungrounded)

Inside the distributor is a Hall Effect Sensor, it pulses 12volts on and off as the distributor shaft turns, one pulse for each cylinder
The TFI module then pulses the Coil's - terminal based on the pulses from the distributor's sensor

So only 1 spark from coil means its losing the 12volts
OR
The TFI module is not pulsing the - wire at the coil
Which is either a bad Hall effect sensor or bad TFI module
ASSUMING, you have watched/seem the distributor shaft spinning while cranking engine over, distributor gear's roll pin can shear off, so it no longer spins with the engine, so CHECK THAT