The suburban will start and shut down Replace throttle body ask for later and fuel pressure is holding 40 pounds

If it won't hold pressure my first thought is the fuel pressure regulator. It is on the back of the motor, under all the wiring. It is behind the throttle body and next to the intake manifold on the 5.0 liter. You can get to it without pulling the manifold, but you have to take all of the hoses to the throttle body off to get to it. Should be either chrome or yellow in color.

The fact that it will start with the throttle body cleaner means that the PCM is attempting to start the engine. The fact that there is fuel at the rail and there is pressure may be misleading. There may not be ENOUGH pressure at the rail to do the job. Check the fuel pressure regulator....pull the vacuum line off the regulator. If there is any fuel in the line, the regulator is faulty and must be replaced. This is the most likely candidate.

is your security key lamp lit on dash.

Hello: I would check the fuel pressure when this occurs, this year model should have throttle body furl injection. 10 psi should be the nominal fuel pressure. Check the fuel filter. When it quits does it just shut off or does it sputter a little bit then quit, if it just quits it could be ignition, hei coil, module, pick up, check cap and rotor, rotor for a burn spot close to the distributor shaft

First thing i would try is to carry a can of WD-40 or quick start with me and when it quits and won't start, remove air intake hose at throttle body opening, open throttle enough to give a good spray inside throttle body, release throttle, then try to start it . If it starts and runs momentarily, you have a fuel delivery problem. If not you have an ignition problem. Then you can start troubleshooting from there.
Or you can carry something to test for spark. I just find this way easier. Don't know when/if fuel pump has ever been replaced, but not uncommon for them to work when cool and quit pumping when they get warmed up, even though they sound like they are still working. That's where a fuel pressure test would also confirm, keeping in mind pressure may read good when first started but will drop later when warmed up and engine quits.

if any codes buy or borrow a reader --when it dies test and check for fuel --test and check relay --what is the oil pressure no pressure bad sensor will shut you down --fuel filter--egr --catalytic converter-throttle body sensors-throttle body itself ---these are some of the reasons that your truck can act as it does so you will need a code reader multi meter--pressure readers -to test and determine your problem

are you sure you have fuel pressure ? alarm systems usually kill the starter circuit not the ignition you need to put a fuel pressure gauge on the fuel rail you should have about 40-45 pounds of fuel pressure . hope this helps

try the fuel pressure regualtor

If your sure that the pump is good, change the fuel filter and get the fuel injectors cleaned by a quick lube place. It's cheap and will make a world of difference.

Idle adjustment. You didn't state the vehicle, so I will post two possible solutions.

Fuel injected engines typically have an IAC valve in the throttle body. This valve adjusts the throttle plate to be open to a certain extent. The computer can control this valve as need based on the density of oxygen in the air. Remove the throttle body and clean the IAC valve or replace it if necessary. Mechanical (gas engine) experience necessary.

Carb engines typically have an idle adjustment screw on the exterior that may need adjusted. Mechanical (gas engine) experience necessary.