ive got an 89 crx thats acting funny now through out the rpms and my tach jumps all over the place,and my exhaust pops, evn at idle, but other times it runs fine, so ive narrowed it down to ignition or crank angle sensor. i want to get an msd external coil conversion just lookin for some feedback from some people that have used em. thanks

 

It sounds like the ignition control module is faulty. Does it do it in both upper and lower rpms or just one of them. You can have it checked at O'reillys.