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Fuel Pump Codes And Control: Keeping Pressure In The Zone

The first electric fuel pump circuits were very simple. The pump circuit usually involved a relay and fuse. The control side to the relay was typically wired to an ignition circuit or key switch. The control of the fuel pressure was performed with an analog regulator that could keep a static pressure and adjust for loads with a vacuum signal.

Flex Fuel: Ethanol vs. Gasoline

For political and economic reasons, the use of ethanol gasoline in the U.S. has always been controversial.

Modern Fuel Control Diagnostics: Sorting Through The Data Stream Maze

Adapted from Gary Gom’s article in ImportCar.   When confronted with a fuel control problem on a modern vehicle, I’ll normally use short- and long-term fuel trims to determine if the problem is caused by one of many failures, such as a vacuum leak or a leaking fuel pressure ­regulator. If you’re like me, you’ll

The Best Tests For Fuel Delivery Systems

In this article, I’ll explain how the ­basics of testing fuel delivery problems has changed and how some of the most common mistakes in diagnosing fuel ­delivery systems can be avoided.

Misfire Testing with a Scan Tool Tip Clip

In this tip clip, instructor Jim Wilson talks about P0300 codes and misfire testing using your scan tool. He talks about how you would look at certain things such as RPM, MAP, changes in load, and long term fuel trims. He goes on to mention some things technicians should be aware of on Ford and Chrysler vehicles.

Deciphering An Engine Misfire Code

Many changing factors must be met to pass a misfire monitor.

Maximize Your Scan Tool

Are you maximizing your scan tools to their full potential? Don’t let them be just an expensive code reader.

PCV System DTC

PCV systems control crankcase pressure.

Diagnosing Misfires

What if there are no codes and a misfire is intermittent? This is where it gets complicated. 

Diagnosing Driveability Problems

Understanding what comes out through the exhaust valve is critical to solving any emissions or driveability problem.