Chevy tahoe 2003 I have just put a new fuel pump on The car runs good but after 30 min or so it slowly die when it starts to slow down I try pushing on the gas paddle and it does nothing

When the fuel pump was changed, the battery was disconnected as standard practice.Now the Security System needs resetting.

https://www.google.com/search?q=2003+chevy+tahoe+security+reset

..

Any recent engine repairs ? Trouble codes ?

check fuel pump pressure first ,

i would first try to replace the fuel filter.usually there filter accumalates debris in the gas tank especially if you you ru the tank close to empty.filter location needs to be traced from the tank toward the motor.you will see a cylinder inline with a strap.part usually runs around 20.00. also when you initally turn the key before start you will hear a hum for about 2 sec. this is the fuel pump pushing the fuel up to motor.so if you hear this pump is working.

I would suggest checking the fuel pressure when the engine dies. You may have to buy a fuel pressure gauge and carry it with you, or see if letting the car idle for 30 min will duplicate the problem. Could be a fuel pump or relay.

try a new catalytic converter. Had this on a 2002 Malibu.

Ok a quick check. When the engine cuts out and you go for restart it dies within 5 seconds. Next time put the ignition at position 2 (on but not starting) and wait one minute, then start the car. If the engine again runs for 30 seconds before cutting off this tells you its is a fuel problem. If the fuel is supplied slowly it fills the carburettor fuel bowls and when the car starts it quickly uses up these local reservoirs of fuel faster than they can be replenished. When you try to restart immediately there is only a tiny amount of fuel and so it used up almost immediately. By leaving the ignition on 2 for while it gives the pump time to fill the carburettor bowls and this takes a while longer to run down when the engine starts. Just before moving on does the car have a choke OK remove the low tension connection to the coil, basically remove any chance of a spark. Put a big old towel around the carb. Now remove the fuel line at the carburettor and put ignition on 2 to engage the starter pump. Listen to pump operation and look at the rate of fuel being pushed from the disconnected fuel pipe. If the flow is slow check on pump and filters.

dying fuel pump, causing insufficient fuel to reach injectors, when you try to accelerate.

check for 12v constant at your fuel pump if you are not getting that replace your relay.
if you are getting 12 volts at your fuel pump the fuel pump is possible to run tuel it gets warm then shut down to a lower rpm I would then replace the fuel pump

hi i have a 1997 chevy tahoe that starts but won't stay running i have changed fuel pump, fuel filter,relay ,spark plugs, and just changed rotor and dis. cap ready need some help to figure this out please.