My 1992 Chevrolet Camaro RS 5.0 l is having idle issues it wants to die but straightens itself back out it was running decent till I recently replaced the plugs,wires,cap and button along with water pump upper and lower radiator hoses and fuel filter along with the battery cable bolt for positive side cause it was stripped. I haven’t had the car very long and I’m trying to figure out why it’s still hard starting and idles sometimes terrible. I put in a bottle of stp carburetor and injection cleaner on last fill up. I usually put unleaded plus in it but accidentally put regular unleaded in it. Could that be causing this issue or could it be something else. I’m almost out of ideas. I’m replacing the thermostat here soon had to order one.it has tbi and automatic 114,000 miles and all stock as far as I know

 

In order for anyone here to provide you some direction, you need to provide much more detail.
What engine/trans? Is is stock? Is it TBI or TPI? How many miles on it?

If it's not stock, what mods have been done?

Did the car run OK previously?