1997 k2500 Suburban 5.7L - I have to press fuel pedal to floor before it will start.

You should start by checking fuel pressure. Fuel pressure should be 56 to 63 lbs with just the key turned to on. Let it sit once fuel pressure builds up to see if it bleeds down. If it bleeds down then there is a problem in the fuel delivery system.

I will check pressure in the morning. Last check it was holding at 58/59 psi.

I remember hearing putting the pedal to the floor kills any fuel signal in the event of flooding , maybe from you rowe ?

Fuel pressure holding at 58/59 psi. Issue still- Cold = starts right up. After warm = Engine just cranks until I press pedal to floor, then starts and runs fine with the smell of a gas.

So fuel pressure is not the problem. Vacuum leak? Check for vacuum leaks along the intake and plenum while the engine is running.

All vacuum lines are good and check plenum - No issues. Update - I have replaced plenum,spider injection,fuel pump and send unit, new fuel filter, regulator, plugs, distributor, wires and reprogrammed ECM

Have you checked for any codes? Also another place to look is at the wiring harness that runs to the throttle positioning sensor. Wires like to break up by the TPS. This would not be a visual check as a wire will break inside the insulation.

Yes I hooked up my scan tool-No codes. If there's miscommunication to TPS, that would throw a code?