1990 Taurus sta wgn 3.8. Sprayed starter fluid in EFI port, car started and ran for 5 sec, won't start again

First any chance the vehicle could have gotten rodent damage, chewed wires, where it was parked while it was dead? I would check for spark if the starter fluid is doing nothing

Chances are its an ignition problem if nothing happened by using starting fluid. Have you pulled the plug wires and checked for spark ?

Check your PCM fuse

Sometimes it takes awhile to prime itself trying again never hurt. the other thing that is possible is that the tank bottom had contaminates in it which were sucked up into the line when it was so low. these can get caught anywhere in the fuel line. I would get a new fuel filter(good to change anyways) the debris or contaminates would likely get trapped there where it is suppose too. it could have stopped it up. if you dont have the 10 -20 bucks for a new filter you can still pull it and try to free the debris by rinsing it with gas the opposite way and reuse. worse case scenario you may need a new fuel pump.. could have burned it up. it happens.. or the debris was large enough to stop it up. either way it sucks because replacing them are never fun. good luck

try to check your starter and ignition.
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FGTech Galletto 2-Master

check your battery first, if not replace your starter.

Turn on key and have someone listen by back of car for fuel pump running it will only run for 5 or 10 sec with each turn of the key. Not running check fuel pump fuse and fuel pump relay. Take another relay out from another spot and swap them to see if it works

did you reconect the air in take hose .some times if the air flow sencer is not geting air flow the car wont start

check the fuel filter first , then the fuel pump

the most likely reason is a failed fuel pump, plugged fuel filter or defective fuel regulator-you need to have the fuel line pressure tested-you can get the use (free) of a guage set from most commercial auto parts stores.