[Walt Fricke]

The DME controls the fuel injectors and the spark. So if the DME relay fails, the DME doesn't get its 12-13VDC supply, and you won't get either a spark or fuel because no signal is sent from the DME to the injectors to open, or to the spark coil to fire.

The cylinder head temperature sensor can fail, but that usually means really hard starting, and I think generally the engine will run, albeit not very well. If you are getting spark (easy to check) and fuel (not quite so easy), then I'd look at CHT replacement. The ether squirt will be diagnostic here. Your '88 should have the two wire CHT sensor, which is said to fail less frequently than the single wire ones the '84s had.