MercedesBenz fuel pump relay problems are more common and can make it appear that your fuel pump has failed. Contact Burdi Motorworks to Schedule an Appointment! Schiller Park Complete Auto Service & Repair . 904 reviews . Get to know the signs of a bad Mercedes fuel pump and react before you suffer an inconvenient breakdown. 1. The engine does not start This symptom is very obvious, but too general since anything could be a cause for your vehicle not being able to start. But if your engine does not start, before you start testing anything else, go to the next step (#2) and listen #2. No noise from the fuel pump Thisvoltage comes from the ignition switch. The fuel injection computer then Grounds circuit 1. This activates the fuel pump relay to pass current from circuit 4 to circuit 3. Circuit 3 is the one connecting to the fuel pump (via the inertia switch) and delivers the voltage/current it needs to activate. Before this voltage reaches the fuel Ifthe fuel pump hums and the car starts, the fuel pump relay is failing to close. That relay should be up under the dash above the passenger's right foot. Look it up on a parts website so you know what it looks like. If a new fuel pump relay will not close either, then we go to the #2 suspect, which is the engine computer. Checkthe rubber fuel hoses. My 1983 BMW 320i's rubber and cloth braided hoses looked fine, but had become somewhat porous and were sucking air bubbles through the sides causing it to die frequently while driving. Your issue could also be a bad fuel pump relay, bad fuel pump, clogged fuel filter, or a bad mass air flow sensor if it has one. Vay Tiền Trả Góp Theo Tháng Chỉ Cần Cmnd Hỗ Trợ Nợ Xấu.

when a fuel pump relay is bad