Engine turns over but won't start

This sounds like a security system glitch that got straighten out when you used the extra key.

https://www.2carpros.com/articles/how-to-reset-a-security-system

When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down these guides and report back.

If you have spark and fuel, it should run unless the timing is off or there is no compression.

I have to start with a couple simple questions. Is the spark to the plugs a good hot blue snapping park or is it more orange or white? Also, I understand you are getting fuel, but have you checked fuel pump pressure at the fuel rail? It could be too low or the regulator may be allowing all the fuel to return to the fuel tank.

Let me know.

Joe

As long as you used high pressure hose, it shouldn't. Here is a how to for checking pressure. It is a video and directions. Check it and let me know what you find.

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

NOTE: You will need a gauge. Most parts stores will lend or rent them to you.

Joe

Check this guide out.

https://www.2carpros.com/articles/car-cranks-but-wont-start

let us know

Sorry!

Get a starting fluid/ether/better off gas in a spray bottle and spray into the carb or the throttle body on an EFI. Did it start and die? If not disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 in away from ground have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, cap and rotor /distributor pick-up coil, ignition control module, ECM, Ignitor camshaft and crankshaft sensors- Note: If it doesn't apply disregard it

HAs the check engine light come on? Also, it sounds like a bad miss. Have you mentioned it to the shop that did the work and was it running this way when you first picked it up?

Let me know.
Joe

Recheck to make sure nothing was left unplugged such as injectors. Check for spark and fuel to the engine.

You need to test the fuel pressure and system to determine if it is the fuel pump or other fuel related problem.

A bad engine coolant sensor, MAF or some other sensors can cause the problem as well.

If the MIL is inicating, get a scan done to retrieve the trouble code to find out if it is related to the difficult starting

Iac valve will not prevent truck from starting.

Fuel pressure is my first check, see if it has at least 45 lbs. If not, you need to check the inertia switch, wiring and relay.

Roy

You need a fuel pressure gauge.
Rf lower kick panel is the location of the inertia switch

Roy