fuel pump cut out

[27Skulls]

Had a new Denso 285 L/hr installed in new tank in July. Also, new Casper's HW kit. Since then, have had problem with car cutting out, and at times, when parking and try to re-start, no fuel pressure, no pump run. I've replaced the stock FP relay with Casper's FP upgrade relay and splice connector. On one occacion, I eliminated the HW relay and car ran great for several weeks. I've since, returned the HW kit to Casper's for them to inspect for any problems. Even without the HW kit in line, still having same issue with fuel pump. Has anybody had a similar situation as this, and if so, what in God's name was done to soleve problem? I'm about ready to toss the Denso and go back to AC Delco OEM setup. I also removed both connectors from the ECM and thoroughly cleaned and dried all of the terminals.