Changed my TPS & IACV now truck wont start unless given gas

sounds like a bad fuel pressure regulator

go to www.reliable-store.com you will get all info and solutions there definitely

have you checked the fuel filter

Hi, under the hood you will have a electrical box with about 4 relays in it. You will find one that is marked fuel. The relays are the same, so try changing 1 with the fuel one. They should be marked on the inside cover. This happened to me, and after switching relays, it was fine. I bought another for $11.95 to carry with me. Mine was a 2000 Silverado 1500. Please get back to me and let me know if this does the trick!
Sincerely,
Shastalaker7

have you checked the crank position sensor? when this baby goes the engine will start and run for one or two seconds then die like its out of gas.

Also the ignition switch may be suspect.

I would look at both the throttle position sensor (TPS) and the Idle Air Control valve (IACV) associated with the throttle body. Determine that these are both functioning as they should before moving on with the search.

Replace the pick up coil in the distributor,this is the problem.

i want to give you the right answer but the only thing i think of is the mass air flow sensor.

its oyur iacv or idle air control valve

Hey Jruthesq

The 850 is equipped with an Idle Air Control Valve (IACV) which supplies the engine with air when idleing (a necessity since the main throttle body valve is completely closed when no throttle is applied, thus the engine would lack air without the IACV when idleing). The IACV is suspended in a rubber mount on the front of the throttle body itself, and is easily removed and inspected/cleaned. If it's dead a good cleaning usually gets it going again. Also make sure that the air from the IACV is unhindered on its way from the IACV to the throttle body (it's actually common for the holes in the throttle body to be gunked up so bad by hardened carbon deposits that one sometimes needs a nail or even a drill to open it up again).

Just thought I'd mention this since you said that the gas needs to be feathered for the engine to start. When you press down on the gas the main valve in the throttle body opens up, closing the IACV and supplying the engine with enough air.

Oh and if your fuel pump relay is a green one marked 103 you should replace it with the new and improved red one. The relay is located under the fuse box cover under the hood. Remove the 4 torx srews holding the cover in place and you'll see the relays under there.

Good luck mate!