basically you need to do some investigating.

Run the computer codes, the Key on/off routine should work on the OBDI system. that will give you an area to look.

If there are no codes then you will have to verify fuel/spark/air and see which is failing.

No one is going to be able to remote view the answer without more info,

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.