94 chevy 350 occasionally cranks and wont start

[Whitechev]

Ive got a 94 350 tbi
It will randomly not want to turn over sometimes, it will crank but wont turn on runs fine whens its on, had the trouble code 54 come on then go away. previous owner said the fuel pump was done and I’ve changed the fuel pump relay. Not sure what to do I’m looking for some guidance thanks

 

[PlayingWithTBI]

What's the fuel pressure when it starts/runs and when it doesn't?

 

[thinger2]

Always start at the battery cable.
The facory plastic coated terminal has 4 lugs cast into it.
They get worn down and make an i termittant contact.
The weight of that cable chews up the lead on the battery.
When you try to tighten that down, the plastic part bottoms and tightens before the metal part makes a solid connection
On any GM sidepost battery with old wires the first thing to do is cut the plastic off of the cable ends and it will be green fuzzy crud.
Cut all of the plastic off.
You are left with a "ring" terminal.
Clean it.
Get a 3/8 16 x 3/4 bolt and a nut.
Run the nut all of the way onto the bolt.
Make sure that the ring you have left will seat and not get hung up on the plastic outer ring of the battery.
In other words, make sure it will make contact.
You may need a washer
Take your new bolt with the nut run all of the way to the head and put it throgh the batery cable.
Finger tight that.
If you go crazy you can punch it throug the battery
Its a 2 buck fix that keeps you from chasing intermittant problems.
Its the battery cables and the grounds my freinds.
You cant diagnose a TBI if it has intermittant power and loss of ground.
Its the battery cables and the grounds.