1991 Gta 5.7 wont start if i let it sit for a dat and come back the next morning it will start once and then wont unless i spray some starting fluid in it. I have changed distrubator, injectors, fuel pump, regulator, ignition module, idle air control, and a few other parts. i put a inline glass filter on it and saw that gas was coming through but then just going right back in to the tank. Any ideas thank...

 

Might want to see if there’s a check valve on the return line. However the pump should prime the system with key on. What type of fpr do you have? Diaphragm leaking? Areo will bleed back on you. Just a thought, check the 02 and temp sensor. Put a gauge on the rail to see if it holds pressure and for how long. Pull a couple plugs to see if their wet but I don’t think its injectors. Good luck I hope this helps a little.