IGn Problem 79 Bronco need some help

My plw truck quit running and its electrical. I have no spark what so ever while cranking but when I release the from the full right position it acts like it wants to fire and there is spark then.NO spark when its turned all the way to the right when its cranking.
We have spark coming out of the coil when the key is released and to all 8 plugs when the key is released.
We have put in a new coil and 2 new brain boxes.

ANy ideas???

Tks Tore

Could be the magnetic pickup inside the distributor or another possibility is the ignition switch. Good luck.

I say ignition switch too.

I've had this problem. It is most likely the ignition switch.

Also make sure the connections are good on the fender mounted solenoid.

Tore wrote:My plw truck quit running and its electrical. I have no spark what so ever while cranking but when I release the from the full right position it acts like it wants to fire and there is spark then.NO spark when its turned all the way to the right when its cranking.
We have spark coming out of the coil when the key is released and to all 8 plugs when the key is released.
We have put in a new coil and 2 new brain boxes.

ANy ideas???

Tks Tore

ohm test the pickup, it has to be between 400 and 800 ohms, 801,or 399 and its junk, any where else its ok,as long as its between.

then test power at red and whit wire. white is run,red is for crank< if this is good its not switch

My vote is ignition switch. The way the start system is designed it has two separate circuits Start and Run. Start uses full 12 volts to Coil and Run uses ~9 volts to Coil. They are controlled by the ignition switch. One side of the your switch is bad. You can check this by measuring voltage on the + side of the coil. Run will have 9 volts and start should be 12 volts. If none in start mode then replace the switch.

Thanks for all the suggestions. Going tomorrow and try again. Really appreciate it.

Tore

Only other thought.....
If you do change the ignition switch, get an NOS one off ebay.
The parts store switches suck.

I had the same problem a few years ago on my pickup truck it ended up beeing the dura spark box.

It was the dist pick up.
Tks guys Tore

Cool.....
Good call Boss429.

Only times I've had a distributor pickup go bad it would fire when cold and die when hot. I learn something new every other day. Thanks for the education.

BOSS 429 wrote:

Tore wrote:My plw truck quit running and its electrical. I have no spark what so ever while cranking but when I release the from the full right position it acts like it wants to fire and there is spark then.NO spark when its turned all the way to the right when its cranking.
We have spark coming out of the coil when the key is released and to all 8 plugs when the key is released.
We have put in a new coil and 2 new brain boxes.

ANy ideas???

Tks Tore

ohm test the pickup, it has to be between 400 and 800 ohms, 801,or 399 and its junk, any where else its ok,as long as its between.

then test power at red and whit wire. white is run,red is for crank< if this is good its not switch

Thanks Rich