Anyone know why this would happen?

[zoe60]

I got a new distributor cap and rotor, installed them and now I have unbelievably bad engine noise in my stereo. I put the old stuff back on and it's back to normal. Ordered higher quality ones online, put them on and the noise is back! Guess I'll just stick with the old stuff for now. I do have an aftermarket high performance ignition system and an MSD coil. I also have a cheap Jensen stereo and a cheap 5 channel amp. Hope this doesn't happen to anybody else, it is very aggravating. Oh- It's an '89 carbed Festy

[shampooking]

got a ballast resistor inline with your ignition coil?

could also be your disty condenser is bad already; the old stuff is sending a weaker signal so it doesn't reach the audio unit. which goes if you put on a new cap and rotor, sparks are better and stronger hence the noise.

[zoe60]

No, there isn't a ballast resistor. The wire fell off of my old condenser so I replaced it with an old fashioned one like on a car with points. For the fun of it I hooked a 1000 uF capacitor from the + side of the coil to ground and it didn't help. I may try to find an original condenser to eliminate that possibility. It's been running great for about 4 years without a ballast resister so I don't think it needs one. Thanks for your help!

[Flyin4stroke]

you can try putting a noise reducer inline with the radio.. I used to get this in my f-150 but added a noise reducer behind the radio and it fixed it.. They sell them at the autoparts store and best buy has them i believe...

[zoe60]

Thanks. I was thinking of trying one but couldn't think of where to get one. Radio Shack doesn't sell them anymore.