G10 won't start I'm stumped

[stylesdude]

Okay, first its a 96 g10 1500 350 vortec.
mileage is around 167000
was driving engine died, coasted to stop and would not turn over. so i ended up changing the fuel pump, still no start.
got spark, fuel, engine turns, checked fuel relay(ok)

my mechanic ran a diagnostic scan, while the key is in off position he is getting map sensor reading airflow engine temp etc. as if it was actually running, when key turned on readings act as if the engine is off. someone told me that the battery could cause this if the charge was too low, essentially confusing the brain box. is this possible?
if so what's the next step if the battery is not the problem?

[gmtech1]

Has anyone load tested the battery on this vehicle? Low voltage will cause all kinds of problems.

[stylesdude]

that is going to be done tomorrow morning, thank you. i will post the result when it is done. thank you.

[stylesdude]

thanks for the help, new battery worked, but apparently someone else has been under the hood and rearranged the relays. so once i put those back in their places it works perfectly. thanks again.