i have had a problem with my car for a few days now. it feels like the opti is going bad, or the spark is getting blown out. this only happens with the MSD digital 6 hooked up and the engine turning about 4000 rpm making about 8psi. when i took the blower belt off and test drove it, it felt better up to about 5000rpm then it did the same thing, breaking up, kinda feels like the soft touch rev limiter.. when i disconnected the MSD and ran all stock ignition with no blower ran great.. then put the belt back on and still ran great. all of sudden i went to take off from a traffic light and the car died. got it over to the side of the road and checked fuses, bad ignition fuse. replaced the fuse hooked up the MSD and got it home running ok, except for the breaking up wheni lay into it.
what can cause the ignition fuse to pop if it doesnt look like any wires are burnt? short somewhere, no idea to look....
and have you guys had problems with the MSD boxes?

 

Did you ever find the problem to this? Mine is doing the same thing right now. Can't find any problems. Been searching for two days now. I've bypassed the MSD and it still pops the ignition fuse. Tugged, pulled, wiggled all the wires with the engine running in the driveway tonight and it runs just fine. I'm afraid to drive the dang thing because I got towed home twice yesterday.

 

i have this issue as well. i suspect there is some wire getting hot near a header.

 

Mine popped a fuse and it was because the bundle of wires that run next to the passenger header had burned through. I had it towed too and thought my opti (~130,xxx miles) went out. Replaced it and it still wouldn't start. Found the fuse was popped. Fixxed the wires and haven't had a problem since. I have only put ~1000 miles on the car in the last 2 years though.

 

back when i had this problem i couldnt figure what would make the fuse pop. after looking and testing for quite a while i decided to pull the front of the engine apart.. i suspected the opti wheel becuase it had high mileage and had never been changed. i read a few posts, didnt point in that direction but just did it to reasure myself. when i changed the engine i put a new cap and rotor on thats it.. well once i got it off i noticed that there was dust all over the wheel and it looked like it was coming from the opti bushing that was kinda torn up. bought a new GM assembly and put it back together and the car runs amazing. 13psi 567rwhp 11.01 @125. new opti has about 3000 miles on it. not to say it will fix you problem but i went with a hunch and it worked out....

 

So far the only thing I've changed is the ignition control module. Still haven't found anything wrong but I've been tempted to swap out the cap/rotor for the heck of it.

I'm only driving the car back and forth to work at this point, haven't popped any fuses since that day.