You hop in your vehicle, turn the key, and you hear the motor turning but it doesn’t quite start. What gives? Well, you know the starter is good because the motor is cranking so it’s either fuel, spark, or compression. Now, with modern vehicles spark isn’t much of an issue because coil on plug systems are much more reliable than the older distributor based ignition system. Compression should also be a non-issue unless you overheated the motor and blew a head gasket. This leaves us with fuel as a probable culprit. The fuel system has many components including the fuel pump, fuel injectors, fuel filter, fuel lines, and wiring. Instead of rushing into a fuel pump replacement, make sure every other part of the system is working properly. This will help you avoid a costly, time consuming, and unnecessary repair.

The best way to begin a system diagnosis is by doing a fuel pressure test. If the pressure is good then we know the fuel pump is good and everything leading up to the fuel rail, thus helping us pinpoint the problem. By conducting a pressure test, what we are really doing is testing the pump. There are a number of ways to test the fuel pump depending on what kind of vehicle you have. Let’s begin by having you look at your fuel rail. The rail is the long metallic object that distributes fuel to the injectors. If the vehicle has a 4 cylinder then there will only be one rail, a 6 or 8 cylinders, 2 rails. Now look to see if the fuel rail has a Shrader valve. A Shrader valve is similar to a valve stem on a tire but its only purpose is for you to check fuel pressure. Most of the time you will find a cap covering the valve to inhibit dust and dirt from getting in. So if your vehicle has a Shrader valve, follow the steps below. If not, skip this section and read on.

Read the rest of this entry »

Related posts

• Car Radiator and the Engine – BFF
• How To Get Your Car’s Engine To Temperature
• Oil Pressure Gauge