Car idles good, then VERY SUDDENLY dies

ALRIGHT! So, sorry for the hiatus there. We're both trying to troubleshoot with minimal tools, and it's cold as all hell here in GA. But I think we may be on to something.
We started by bleeding the brakes so that if this thing does decide it wants to go, we can go ahead and test drive it. All fresh brakes, new ford motorsport springs, SR suspension shocks, subframe connectors, underdrive pulleys, and 90% of the gaskets look FRESH. Even a new heater core that hasn't even been plumbed yet. This car may have been sitting for however long, but whoever was trying to get it going again paid good attention to the drivetrain. Body looks a little rough and mismatched but, for $4500 it was a steal mechanically. Probably $2-3000 in new parts. I'm 99% positive (owner mentioned it) the tank, filter, and the fuel pump are new, visually the tank looks new, fuel pump sounds healthy, and I have pressure at the schrader valve, fuel sending unit works too.

I have not checked codes - I have an OBD1 checker but I couldn't seem to get it to read anything, I was probably plugging it in wrong but it was getting late so I had to pack it up by that point. I'll work on that next!

Previous owner had videos of it running and idling for 2+ minutes but then claims he messed with the timing or something and it started acting up.

Bought a timing light and set it at about 12 degrees, car seems to do good around there. Also checked virtually all vacuum hose locations to rule that out. had to reseal the PCV valve (behind intake) as well as replace some of the nipples on the Exploder intake that had cracked up. Set the idle as best as I could between the car dying and got it to around 800-900 RPM which I'm happy with for the time being.
The car seems to run alright, when it does run. We got it to idle for a period of about a minute, maybe more, until it succumbed to whatever issue is at hand.
I think Noobz347 / Mustang5L5 may be right and I may have narrowed it down to the fuel delivery. The injectors are one of the FEW things on the engine that appear factory 19 lbs. They look like they've seen better days, but what makes me suspicious of them is this sound I keep hearing.

1 - When you turn key, obviously you hear fuel pump prime in the back, but you also hear a HISS from what I believe is one or more of the injectors letting off pressure straight into the cylinders. It doesn't happen every time, but it is repeatable, and it's something that I don't think I hear on my fox that runs great.
Could this just be the sound of the return line? I was under the impression that it stayed pretty pressurized. It also seems to do it more after cranking rather than just priming the pump.
2 - After the engine dies, sometimes it practically refuses to light up from that point. Sometimes it cranks right up, others it cranks and cranks with no fire at all.

Could I theoretically test this by removing the upper intake and fuel injectors/rail, and turning the key to see if they spray fuel out with out cranking?

Mustang5L5 said:

The rail should hold pressure for a little bit. Usually they bleed down eventually due to the check valve/nipple in the fuel pump.

But if you lift the rail up off the lower and pressurize it, you may shoot a few injectors out of the rail at 39psi.

However if you pull the upper off, the noise should be pretty loud in the port of the injector is just spraying off. If you have a gauge on the rail you can see if the sound matches the pressure falling off. You should also be able to smell it.

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here’s a pic of the engine bay just for attention, or if there’s something obvious I’m missing!
So we checked the fuel pump at the rail, stays at a pretty solid 30 PSI and goes up to 40 when pump is first engaged. Stays at a good pressure while (shortly) running too. At least that confirms the pump is good, and that it isn’t leaking down.
Trying to run through the surging idle checklist and eliminate things. Not sure if i should be there or at the cranks but no start, because it does crank no start sometimes

Vulpes5.0 said:

here’s a pic of the engine bay just for attention, or if there’s something obvious I’m missing!
So we checked the fuel pump at the rail, stays at a pretty solid 30 PSI and goes up to 40 when pump is first engaged. Stays at a good pressure while (shortly) running too. At least that confirms the pump is good, and that it isn’t leaking down.
Trying to run through the surging idle checklist and eliminate things. Not sure if i should be there or at the cranks but no start, because it does crank no start sometimes

Click to expand...

Had to fix the throttle cable, couldn’t actually press the pedal down 100% since the cable was stretched. Threw a homemade plastic “bushing” on there i made from a door lock knob cut into a C-shape with a dremel, along with some zip ties, so now I can do the flood clear. That under dash throttle cable area is a pain….

Flood clear seemed to help on the times that it would crank no start. Popped cold air intake off and it smells of fuel at the butterfly, AND smells like fuel at the oil cap as well. I’m pretty convinced that this is something to do with injectors, but didn’t get a chance to pull intake off tonight. Check engine light did not come on when we got the car to idle for a period of about a minute. Do these cars blink only when you dump codes or blink every time you get a fault?