97 GMC Vortec 4.3 Almost Start Condition - Stumped

98 GMC 1500 V6 4.3 Vortec 120K miles
Sat for 8 years in Pacific Northwest (rain)
We are in a remote-ish area without electronic diagnostic tools.
Dropped tank, new non-OEM fuel pump, new spider assy, new dist cap and
rotor, plugs. Improved from no-start to almost-start: runs briefly if gas sprayed
into air intake. Gas pressure seems good enough to start (no gauge - we
cracked the fuel line - indicates decent pressure).
Question - what is the logical next step (long drive into town)?
Option A: check codes and check line pressure accurately first
Pros: Fastest and wisest.
Cons: Need to $$ on gear we will never reuse. No guarantee it will give codes
because it wont run long enough; We know we have 'some' line pressure -
enough to start at minimum so more precise reading doesn't necessarily help
resolve the no-start.
Option B:
Try 'one more thing'.
Pros: Any $$ invested is directly in cart parts that will benefit long term.
Cons: I have no idea what the 'one more thing' is that makes the most sense;
Assuming enough fuel pressure to start and the fact that it will start with gas
assist - what is preventing a new injector assembly from outputting enough fuel
to start? ICM [failure] seems to be the only part that would cause this condition.
Or? And, if true (ERG, cam or O2 sensor and/or worn Distributor shaft will only
affect performance after start) can we test the ICM or is it a buy it and try it
proposition?

Thanks for reading! :-)