It won't hurt the engine, But it can cause it not to run are even start.
Incomplete combustion
no srry
On an interference engine you can have internal engine damage when you attempt to start it. On a noninterference engine it may not start or it may backfire, or miss, if it does start.
Start and run, no. Cough, backfire, yes.
A faulty gas cap could cause the check engine light to come on but it would not cause a rough idle or engine noises. Start with having your local auto parts store read the codes. The codes will help determine why the check engine light is on.
A faulty engine coolant temp sensor can cause that.
It's lean. You have to figure out why.
to much fuel is going to the engine for it to burn it all
Faulty light bulbs, damaged engine.
If this is a Power Stroke engine, the most likely cause is a faulty crankshaft position sensor.
A 1999 Ford Ranger may be hard to start and backfire due to several potential issues, such as a faulty ignition system, fuel delivery problems, or a malfunctioning sensor. Common culprits include a failing fuel pump, clogged fuel filter, or worn spark plugs and ignition coils. Additionally, a vacuum leak or issues with the engine timing can also contribute to these symptoms. It's advisable to perform a diagnostic check to pinpoint the exact cause.