IM trying to help buddys daughters car run. It has a quad4 auto. This is an unusual no start situation.

Sunfire came to me with a crank sensor code on and no start. They brought it to me from their family mechanic, who had it 5 months and informed them the motor was blown, and 2500 for used one installed. I installed new sensor, cleared code, code hasnt returned. Still no start.
the girl said she drove at highway speed, and car started running rough--and shaking--and die. No prior warning signs so she claims.
if you crank cold, car runs for 1 second, and dies.
if you recrank immediately, it will stumble and fire but not start.
if you let the fuel pump sit for 5 secs with key on, it will start for a second again. If I introduce propane into the intake, the car will idle. But if I try and idle it up, it will misfire due to lean unless I up the propane.I would consider that normal. If I let the car idle to normal operating temps, and shut off the propane, the car will run on its own, and die as soon as you increase throttle. Now the things ive tested.
compression is 185 all across.I changed plugs with known good used ones I had. I put in new fuel filter I had as heavy rust on old one. It wasnt clogged. Fuel rail has no schrader valve, so I could not test rail pressure, nor test regulator. (Regulator seemed to not be full of fuel).
my scan tool said fuel pump was at 40% duty and I saw tool change on the open loop closed loop fuel circut. If I ran the car on more propane I saw duty cycle increase. Map sensor reaDS 33Kpa at idle. No detonation.
i do not have a noid kit, but I conclude injectors fire as car will idle warm on its own. Can they be plugged? Doesnt go with the sudden condition. I cant help but think the computer is commanding fuiel bypass. But why? Just a trickle of fuel is getting into the cyls.
all this idling and running, and I even drove car up onto car hauler today, and no MIL's. Passlock is not blinking.

i took a fuel tank out of a smashed car that ran, and put it in to eliminate the possibility of weak pump/contamination.

i have a used fuel rail/injectors/ harness, and regulator from same smashed car I can stuff in to test.