Electrical Why does my fox body keep frying eecs

I have a 1990 mustang gt 5.0 with a 5 speed it had a chip in the eec but from my investigations I have found the the engine is stock

New distributor with pip and tfi only year old
new ignition coil with plugs and wires
new fuel pump
I have been having problems now for 2 years
The first time the car was still running and driving fine but I had codes that would not go away I ended up narrowing it down to the eec being bad

Replaced it car was great drove it as my daily all summer no problems until one morning go out to leave for work car wouldn't start had spark but fuel pump and injectors weren't working

I looked through all the wiring and couldn't find any shorts or bad connections looked at all the fuse able links.

I just put the eec back in after getting rebuild again I thought maybe the chip was causing it and tried running it without the chip and didn't even make it out of the garage and same thing fuel pump won't prime and injectors arent pulsing.
eec doesn't even seem like it's booting up since I'm not getting the CEL when I turn the key on.

Am I missing something obvious or do I really have to dig into this thing more.

Thanks

JMG9350 said:

Have you checked the ECU ground wire near the battery?

Click to expand...

Yes it is intact and clean
I've also ohmed out all the grounds at the eec plug and they all come back with less that 1 ohm to the frame
Im thinking there has to be a short somewhere but it's not a dead short since the car was running but as soon as I drove the car even a couple feet it shorted out somewhere and fried it?
I just don't know where to start looking since it isn't consistent