Dear Scott I have a 2006 chevy malibu ls with 3.5lt v6 with auto transmission and has aproximetly 214000 miles on it I bought it from my shop teacher and was well token care of but sometimes when I go to start it after driving for a little while like say if I come in and out of a store it will turn over and then die immediately however of I pump gas immediately ter turning over the key it will start shop teacher said to run fuel injection cleaner through it did that but still has same issue any suggestions
When it's cold, does it start and stay running?
If so, your fuel injectors may be worn out and are dripping gas -cold engines need more fuel to start, but hot engines need less. Pushing the gas pedal while starting it opens the throttle and leans out the mixture -you needed to pump the gas a few times back in the day to prime carburetors for starting, first thing in the morning. If you pumped it too much, it wouldn't start, and you'd have to crank it over with the throttle wide open to clear the excess fuel. Modern cars are programmed to behave the same way. I dealt with this when I started my '79 Pontiac this morning.
Check your air filter, clean your throttle body plate and MAF sensor following Scotty's video, Make your Car Run Better with Spray Cleaner, before you go and change fuel injectors. Codes and fuel trims will give you a better idea of the condition of injectors.
That thing is 17 years old. How old are the fuel and air filters? Is fuel pressure OK? Have you scanned it for codes and live data?
Also, how old are the spark plugs?
Spark plugs at about 100k air filter is new no dic codes