What colors are the labels on the coils? If blue, toss 'em. If no, remove the coils and ends, look into the end of the coil and look for oil residue on the brass/copper center piece of the coil. If you have oil, replace it. The oil is what cools the coil packs and when they leak, they overheat and break down under high load.
On some 104's the knock sensor harness is seperate and the harness will come apart allowing the sensors to short, throwing into a fixed timing map that has little to no balls, I had a 111 engine (4 banger) that would drop #3 injector with this issue. (never have figured out the attachment between the 2)
However, I've had more bad coils on 104's than resistor tips and almost as many bad coils as harness's.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.