If it idles up and down it could be the ignition system such as a bad coil or a clogged/bad Air Control Valve/Motor or Throttle Position Sensor. Usually if it runs fine at high RPM then it is not the ignition system and most likely is one of the other two.
Check your vacuum lines. Make sure one is not unplugged, loose, or cracked
mass air flow sensor
no down paymet on the 09 as they don't make a 09.
check and make sure your firing order is right and that you have correct gap in spark plug
Your vats not working correctly If your key is dirty and doesnt make a good connection it will come on even while the car is on and driving down the road
there is an Allen screw and a nut on the throttle cable you loosen the nut and the screw and adjust it to make it idle up or down.
What would make my 1990 camaro run good for 30mins then it doesn't want to start&runs rough& jumpy
No, the steel bumpers from a 1977 Camaro will not fit in a 1978 Camaro, As the 1978 "Bumper" is part of the front end. Taking off the 1978 "Bumper" would mean cutting it off, which would make the car look like something else.
Could be a idle control sensor but your best bet is to get the computer checked and see what codes come up.
IAC + Idle Air Control And yes it can and will. That's what is is designed for.
Abour 3,000lbs. They didn't make a 2009 Camaro.
a firecracker