No spark question

My car is an 87 carbed 302 with a duraspark setup

Cranked it today letting it warm up...It was running very smooth (went to the store and everything) then it just shut off like I had turned the key off and will not restart. Key on I have 12v at both positive and negative coil terminals. Swapped coils to one I had laying around, still cranks but will not fire even with a different coil wire to distributor. Coil is an MSD blaster but everything else is just a regular duraspark setup...I took out a spark plug and connected a plug wire to it...grounded to engine and it isnt sparking when I crank it...I did this with about 5 of them.

Im assuming it doesnt have spark because when I crank it, it doesnt even try to start if you know what I mean. I also have good fuel pressure to carb if that matters

any ideas?

thanks

EDIT...looked on the underside of the distributor cap and it looks a little corroded, but would it cause loss of fire simultaneously to all cylinders causing a complete shutoff?

View attachment 262223

replaced distributor cap and still wont fire, oh well I needed a new one anyways

I took a step back and started checking a few other things and found I had a blown 25a fuse in slot #16

is that fuse ignition related? all my other accessories worked even with it blown...if so could whatever blew that fuse have eaten my ignition box?

this is the one I have

85_SS_302_Coupe said:

I'm not sure off hand if the fuses in an '87 are different than my '85 but i don't think the fuse is your problem. There's a good chance that the Duraspark just crapped out on you. If you're positive that it's wired up properly (meaning that, yes it started and you drove it, but did you hook it up wrong and that caused it to burn out?) and you checked for spark and you have none, then i'd say the box is dead. It's either wiring or a bad box.

For what it's worth, i would rather buy a 20 year old Duraspark ignition off of a junkyard truck than buy one of the remanufactured ones from a parts store.

In case you need it here's the wiring diagram for it.
View attachment 262116

Click to expand...

I appreciate that, yea Ive been driving it since December and plus I can pull the coil wire off the dizzy, stick a spark plug in it and put it close to the engine block and give it direct battery voltage very briefly and it will spark

so youre thinking probably the box itself? Maybe whatever blew the fuse fried the box. My electric fuel pump is wired into my ignition also, maybe not the best idea

Im glad I put it where its easy to get to lol

View attachment 262117

it ended up being the ignition box like you said

thanks for the help