02 GMC Sierra - Crank No Start; Has fuel, spark and injector pulse

Repost

Son has 2002 GMC sierra. 5.3 vortec. 188000 miles

Installed a lift kit, did some mig welding and sandblasting on the frame.

noticed a MIL.
Scan (Autel 808MK) showed misfire on cyl 5 & 7, live data shows some on right bank.

swapped coils on 3 & 5 cyl. misfire moved to 3 cyl.
Then started truck and it ran for a few seconds then died.

Will run on alternate fuel.

tested fuel pressure: 52 lbs.
all injectors get pulse via noid light and audibly with stethoscope
all injector resistances are 12 ohm.(11.6-12.4 is in tolerance)
12V feed on all injectors
cleaned and bench fired all injectors

fuel gauge was on empty, replaced fuel pump, bad float

replaced fuel pressure regulator, couldnt blow through while applying vacuum.

Scan tool reported lost comms with ECM, replaced ECM, married to BCM
replaced crank position sensor
plugs are dry, all get spark. cleaned plugs

new battery


unhooked MAF, no change - @ontheriver

fuel pressure drops to 46# for an instant then remains at 52# while starting, cant do another injector balance test. can bleed pressure off by manually firing with leads - @juergen.scholl

Could it be simple as bad fuel?

Lefts is from gas can. Right is through fuel pump on truck

Why did it run long enough to get to back yard and test coil swap

anyone need 18 gallons of weed killer? lol

Did changing the fuel fix it? That's not the worst fuel sample I've ever seen.
I look for 3 things: 1) Is there water separation? 2) Is it clear enough to see through? 3) Does it smell like turpentine?
I stopped lighting puddles on fire, I learned the hard way that just because it burns on the drive way doesn't mean it will run an engine, lol.