During a fuel pressure test, what should be observed when the engine is shut off?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Study for the NOCTI Automotive Test. Explore a wide range of questions with hints and thorough explanations. Boost your knowledge for automotive excellence and achieve your certification!

Multiple Choice

During a fuel pressure test, what should be observed when the engine is shut off?

Explanation:
When the engine is shut off, the fuel pump stops and the pressurized rail is no longer being replenished. The excess pressure in the rail bleeds off through the injectors, the return line, and the regulator. So the observed behavior should be a drop in fuel pressure after shutdown. A rise would be impossible without the pump running, and pressure staying exactly the same is unlikely because the system gradually leaks down. A readout of ERR would indicate a gauge or sensor fault, not normal behavior.

When the engine is shut off, the fuel pump stops and the pressurized rail is no longer being replenished. The excess pressure in the rail bleeds off through the injectors, the return line, and the regulator. So the observed behavior should be a drop in fuel pressure after shutdown. A rise would be impossible without the pump running, and pressure staying exactly the same is unlikely because the system gradually leaks down. A readout of ERR would indicate a gauge or sensor fault, not normal behavior.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy