Why do injectors keep failing?

1987 Chevy R30. 7.4 TBI.

Had injector(s) fail back in October. Drove me crazy trying to figure out the issue. It got into a really bad lean surge just off idle and would never recover. After a whole lot of tuning and parts, replaced the injectors and the problem went away. Put about 3K miles on it.

About 2 months ago I started to get a CEL for a lean condition at light throttle cruise. Tried tuning it out but no amount of changes to the VE or any other settings would fix it. Issue started getting worse about 2 weeks ago where it started to stumble, and as of last weekend it is now back to the exact same condition that I had with the extreme lean surge. You can watch the O2 sensor voltage drop and INT climbs.

The injectors were brand new GM branded parts. I am getting them replaced under warranty.

What could be causing injectors to fail like this? Fuel filter is new. Fuel pressure is remaining constant at 13psi. I don't run any fuel additives. I pulled the injectors and the inlet screens were totally clean.

Anyone else have TBI injector issues?

Send the originals to MR. Injector for cleaning and flow testing. Maybe he'll be able to tell you what he finds. He's done good work for me.

New injectors showed up today. Lean CEL gone. Stumble gone. Lean surge gone. Cracking the throttle I can see the increase in flow. The old ones didn't do that.