What could be my issue? I have a 2007 Tahoe 5.3L FF 2WD with an Extended crank that goes on for at least 6 sec and then I’ll shut it off and it’ll turn on the next try. What’s crazy is that the truck runs fine after and maintains a consistent fuel pressure between 52-55psi. However when I put key in start position I was receiving 0 psi. I switched the fuel pump relay out and then my fuel pump stood on constantly even after removing the key while truck was off. So for about 2 weeks I had to remove the fuel pump relay after turning it off so it wouldn’t drain the battery. I read in another post this sometimes happens with new relays but while it was doing that my truck had no problem turning on and seem fixed. However, the starter began acting normal and the fuel pump would shut off w/the engine like normal and the extended crank came back! Now to try and remedy the situation I’ve tested the fuel injection connectors with Noids which was fine and that means the signal from the computer is coming thru the connectors. I removed the fuel rail to individually clean each injector and they all sprayed fine and came back at 12.3 ohms when tested w/multimeter. I’ve changed out the oil and filter, new Acdelco spark plugs and wire harnesses, new Evap, and new MAF sensor. I tested the new fuel relay and its working fine. I stuck a tpin in the fuse box where the fuel relay would normally be to test the signal from the pcm and cranked the engine while putting a probe light on the tpin and everything lit up showing the signals good. I jumped the fuel pump from the relay and it turns on. However, it still gives me a long crank before having to turn it off and then it’ll start the 2nd time. So I am thinking of cutting into the wire cover that covers the wires coming from the main fuse box to the fuel pump so I can test the signal from those wires. Can it be the oil pressure switch? I’m so puzzled. Someone help with an answer. Because based off what i mentioned the fuel pump should be fine then, right? So what else could it be???