When the temperature drops below about 55 degrees outside, she wont start. '91 Z28 5.7 TPI.
I have changed pretty much every thing that i can think of. ECM temp sensor, pigtail connector, TPS sensor, ignition control valve, all injector upper and lower "O" rings, fuel rail seals, fuel regulator, ignition module, coil wire, cap, rotor, plugs wires, fuel tank, fuel pump, fuel filter, etc.
Can anyone offer any ideas or solutions?

 

Does it have spark? If so try some stater fluid and see what happens.

RBob.

 

Yes, I have spark. I shot some starter fluid into the Plentum and she tried to fire. So I am down to thinking its fuel related. I can hear the new Fuel pump click on. Every thing else that i can think of has pretty much been changed. There is a sensor on the underside of the Plentum, right in front of the new fuel regulator. Not sure what that is. Not sure if it was just coincidence or what, but it wasnt starting, and I bumped that wire that connects to that sensor. I thought I heard a click, so I imeduiately turned the key and it fired. This morning, I went to stat it about 5:30am. It was about 50 degrees out. She woulnt start. I tried feeling for that wire and bump it to see if it would do it again, ( yesterday, may have just been a fluke with investigating that wire and it starting). it still wouldnt start this morning. i couldnt see the wire due it still being dark out this morning. To date. i have changed, the fuel tank, fuel pump, filter, TPS sensor, Ignition module, coil wire, ECm temp sonsor and pigtail connector, all upper and lower injector o rings, fuel rail seals, fuel regulator,plugs, wires, cap, rotor, water pump, thermostat, steering column, bypassed VATS,. So I am pretty much stumped and just about completely frustrated.

 

Sounds like there is low fuel pressure. There is a tap on the rail to check it. With the vacuum line off it should be between 43 & 47 psi.

RBob.