Failure mode - GM 6.0L V8 Gasoline (GM HD, LY6-L96 2008-2019; Express/Savana vans 2008-2020)

Fuel delivery: pump, injectors, pressure (L96/LY6)

Reliability tier: verified - verify before ordering, see /disclosure/

Symptoms

hard starting after sitting, long cranks; fuel pump whine before outright failure
lean misfire under load traced to pressure drop; injector balance complaints
flex-fuel (L96) fuel system service themes

Compare with the other causes of the same sign on this engine: hard start, long crank or no-start · ticking, knocking, rattle or whine (4 causes) · misfire, rough idle, hesitation or surging (3 causes)

Root cause

In-tank pump modules age with heat and low-fuel running; pressure drops show up as long cranks and hot-start lean misfire long before outright no-start. Injector and pressure-regulator faults ride the same symptom family; the flex-fuel (L96) fuel system adds ethanol-compatibility service items.

Diagnosis

log fuel pressure at rail and at the pump; compare hot vs cold
rule out the sender/module harness before condemning the pump
injector balance or smoke-test the intake for vacuum leaks first

Fixes

renew the failed injector/pressure component as testing dictates; the in-tank pump module PN is a catalog gap (disclosed) - parts records carry the injector and rail ()

Prevalence

common

Parts for this repair run about $45-$200: see them next to the other repairs on this engine in repair costs.