My camaro turns on but slowly turns off, what's wrong?

It idles for 5 sec. Then slowly starts turning off. First I thought it was the fuel pump, but engine is getting fuel. Changed the fuel filter. It's like if air is not getting thru. Changed my MAF sensor, but still doing the same thing.

maybe an intake manifold leak or run-on(deposits in the cylinders)

Sounds like the pump or fuel filter. When you initially turn the key on the pump runs priming the system with fuel. Once the car starts It runs off that prime but because the pump is tired or the filter is very clogged the car only runs off the initial prime and the fuel can't be delivered fast enough to keep up. Spend $8 and replace the filter and see if it fixes the issue, you car probably needs one anyway... get you fuel pump tested for both pressure and volume. It may have enough pressure but if it doesn't have enough volume it won't maintain that pressure.

Bad compression would prevent startup. Bad compression would get better with increased rpms engine cranks at 200 rpm and idles at 600, if it has enough compression to start it has enough to run.