No Spark, need help quickish

ok, so i know theres been alot of threads on this topic lately but i need to figure this out. i am getting no spark, i know its not the plugs, coils or wires. what i need know is... what is the easiest way to tell wether its the PTU or the ECU or the CAS? im having alotta trouble diagnosing this one. it ran superbly last night, then when i go out to head to school this morning, no spark... kinda weird to happen all the sudden dont you think? any help would be greatly appreciated. Thanks in advance guys.

if you had a Service Manual then you could easily test the PTU with a multimeter/voltmeter. i highly suggest you get a service manual. you can find them on ebay for about $20. be sure to get the SERVICE manual, not the owner's manual (which is useless).

try finding a 98 vr-4 's internals for the 6 speed manual transmission yeesh

try finding a 98 vr-4 's internals for the 6 speed manual transmission yeesh
so, what does that have to do with anything?

ok, well its not the PTU, so, do you think it could be the CAS or the ECU?

so, what does that have to do with anything?
Two words

New Bee

ok, so i swapped the PTU last night, same thing... then i got my datalogger, and tried to run trouble codes with the ignition switch in the on position, and it was telling me there was a Serial Communication Error, and after checking all conections 3 times over, i concluded that everything was quite well hooked up. so im guessing i could have fried the ECU? it is a 93 afterall. is this a possibility?

Also, will my JDM vr4 ECU plug right up to my fed spec vr4 wire harness? thanks guys