Technician A says that a rich exhaust could be caused by a hole in the rubber diaphragm of the fuel-pressure regulator on a port-injected engine. Technician B says that a defective spark plug wire can cause the engine computer to supply a too-rich air-fuel mixture. Which technician is correct?

Question

Quizplus · Accepted Answer

Technician A is correct because a hole in the rubber diaphragm of the fuel-pressure regulator can allow excessive fuel pressure to be sent to the injectors, causing a rich exhaust. 
Technician B is also correct because a defective spark plug wire can cause an incomplete burn of the fuel mixture, leading to a rich exhaust. Therefore, both technicians A and B are correct.

Technician a Says That a Rich Exhaust Could Be Caused