Engine will not stay started. I have replaced idle control valve map sensor spark plugs spark plug wires no check engine light is

Engine backfires car will not stay idling idle jumps up and down up and down at the top end have replaced map sensor spark plug spark plug wires idle control valve no check engine light at this time but has plugged in the ECU and got to go back for engine running too lean
Now it seems to have no spark I believe I've put a screwdriver in the spark plug wire and
against the block and got no fire

My car has 200000 miles.
My car has an automatic transmission.

– Engine will not stay started. I have replaced idle control valve map sensor spark plugs spark plug wires no check engine light is