All vehicles now use an electrical fuel pump to deliver fuel (under high pressure) to the fuel injectors and the best way to diagnose this fuel pump is with a fuel pressure gauge.

Owning a fuel pressure gauge is now becoming a must. Which And Where To Buy A Fuel Pressure Gauge For more info on this, see: Checking The Fuel Pump Inertia Switch. So, it's always a good idea to check the fuel pump inertia switch first. In layman's terms, this means the fuel pump will not run. NOTE: A fuel pump inertia switch that has triggered, will interrupt power going to the fuel pump.

You've sprayed starting fluid into the throttle body and your vehicle started, even if only momentarily.Īlthough the above list is a not a very complete list of symptoms, the theme that runs thru' them, and any other related symptom, is that the engine will crank and crank, but not start.

You've done a fuel injector Noid Light test, and all four fuel injectors are getting both 12 Volts and the activation signal.

So you know that the ignition system is not at fault.

You've got spark coming out of all of the Coil-On-Plug ignition coils or coil packs.

Here are a couple of others that are more specific: When the fuel pump stops working, the most obvious symptom is that your 4.6L, 5.4L Ford (or Mercury or Lincoln) will ‘crank but not start’. You can find this tutorial in Spanish here: Cómo Probar La Bomba de Combustible (Ford 4.6L, 5.4L) (at: ). The tests I'm presenting to you here can be easily and safely done (and I've done them lot's of times without any unwanted and unhappy accidents), if you take all necessary safety precautions, stay alert and use common sense.

FUEL PUMP TEST 2: Using A Fuel Pressure Gauge.Ī word of caution: starting fluid and gasoline are extremely flammable, so you need to be very careful around them.FUEL PUMP TEST 1: Spraying Start Fluid Into The Throttle Body.Which And Where To Buy A Fuel Pressure Gauge.

2005 expedition fuel pump install