Assuming they are only fouled, and not cracked ceramics, or center electrodes badly burned down, yes - they can be cleaned, re-gapped and reused.
no The starter should engage whether the plugs are fouled or not. However, the engine may not start if enough plugs are fouled. If you feel that you have flooded the engine or fouled the plugs you may need to clean them before it will start. If you have caused the carburetor float level or other settings to be significantly changed, the engine will flood and it will not start.
Wear. Fouled. Cracked.
if the spark plugs are black because your car is running too rich. your plugs are fouled.
Yes, fouled spark plugs can cause engine shaking, and loss or power. I'm not sure about knocking but I'd guess that too.
Bad fuel,clogged fuel filter,fouled plugs.
Fouling spark plugs can happen when the tip temperature is insufficient to burn off carbon, fuel, oil or other deposits and causes spark to leach to metal shell...no spark across plug gap will cause a misfire. Wet-fouled spark plugs must be changed as they won't fire. Dry-fouled spark plugs can sometimes be successfully cleaned by bringing the engine up to the operating temp.
only if the plugs and wires that replaced them where not fouled most time yes is the answer. after changed start the vehicle and it should be aparent.
spark plugs fouled with oil. blue smoke from tail pipe.
The year, make, model and engine would help us help you.
You have to remove them and inspect.You have to remove them and inspect.
intake manifold gasket is leaking and water is getting on the plugs, plastic piece melts and causes leak
possible fouled spark plugs, bad fuel. check both and if both are good, get back to me.