I need some help with blowing ECM fuse in my 87

[AustinBelair]

I was taking my dad to the cruise-in last night and the truck died while doing 45mph. I swear I heard a noise before it died. A pop, a clank, something. I pulled into the auto parts store parking lot. It will crank but no fire. It's an 87 with the 4.3L V6 TBI and dual tank. I swapped fuel pump relays and same result. I bought the truck a year ago and never tried to use the driver side tank, only the Pass.

I flipped the switch to the Driver side and same result. I poured a gallon of gas in the main tank I've been using. Nothing. I laid under the truck and had my father key the ignition. I didn't HEAR the pump prime but we were on a busy road so I couldn't hear it real well if it did prime. It's like both pumps quit working.

Is there a fuse for the tank selector valve or for the fuel pumps that I am not seeing? I find it odd that both pumps quit UNLESS the drivers side never worked and I didn't know and the pass side died last night. Not sure where to start. Maybe the fuel pump relays on the firewall are dead?

Replaced the pass side tank, pump, tank selector valve, fuel pump relay and still no start.

I just replaced the ignition module in the distributor and the oil pressure switch and it was still not starting. I looked and no fuel at injectors. I noticed when I turn the key on, the pump will not prime but when I kill the key, I can hear the pump run for 2-3 seconds. Still no start. I looked at the fuse box and the ECM fuse is blown. I replaced it and BAM it fires right up and idles beautifully, better than it ever has. Unfortunately, when I turn the ignition off, the ECM fuse blows again. WTH