'94 Chev astro-ECM1 fuse

Hello everbody,just new to AP,looked thru the forums and this looks like a perfect place to be for auto questions!!Anyways,my problem is I've a 1994 Chev Astro 4.3,good van until about 3 weeks ago,It was idling and then it just died,I replaced the fuel pump and it blew the ECM1 fuse.Replaced the fuse and it ran fine for about 3 hours.Looked thru all wiring for shorts,fraying or grounding.Somehow after about 15-20 fuses it ran,for about 2 weeks and now it just keeps blowing the ECM1 fuse. Any help would be appreciated,thank you

There are two ECM fuses- one is 15 amp battery hot- the other is 10 amp ignition hot-- check for rub-throughs on all wiring harnesses and conduits- look for burn throughs at exhaust manifold- check oxygen sensor wires....it might be easy to find or it may be tough- could even be an individual component shorting internally...