What should be done before removing an injection nozzle for testing or repair?

Before removing an injection nozzle for testing or repair, it is essential to clean the area around the injector thoroughly. This practice is crucial because any debris or contaminants present near the injector can fall into the engine when the nozzle is removed. Keeping the area clean helps prevent damage to the engine components and ensures that no foreign objects cause clogging or further issues.

By maintaining a clean work environment, you also promote a better seal when reinstalling the injector and reduce the potential for leaks. This precaution is a vital step in maintaining engine integrity and providing reliable performance after repairs.

The other options, while they may be relevant in specific contexts, do not address the immediate concern of preventing contamination at the injector site during removal.