Multimeter
Seriously.
If
you are installing or fault finding any automotive electrical system,
let alone an electronic fuel injection system, you must have access to
a Multimeter.
At
some point you are going to have to test a voltage or the continuity of
a wire or connector.
Now, it doesn't have to be the most expensive meter available, in fact, you can get a very useable multimeter for less than $50.
At
some point you are going to have to test a voltage or the continuity of
a wire or connector.Now, it doesn't have to be the most expensive meter available, in fact, you can get a very useable multimeter for less than $50.
Voltage
Sometimes you will need to
check if there is 12V or 5V supply at a sensor, or the output voltage
at a sensor.
For example, a throttle position sensor (TPS) usually has 3 wires.
The voltage output on the sensor wire of the throttle position sensor should change smoothly from closed to open with no "bumps" or "falls" in voltage.
Any non-linearity in the output of the throttle position sensor will cause driveability and tuneability issues.
You cannot use a TPS that has a problem.
For example, a throttle position sensor (TPS) usually has 3 wires.
- +5V supply
- Sensor Signal (variable voltage)
- 0V Ground
The voltage output on the sensor wire of the throttle position sensor should change smoothly from closed to open with no "bumps" or "falls" in voltage.
Any non-linearity in the output of the throttle position sensor will cause driveability and tuneability issues.
You cannot use a TPS that has a problem.
Resistance
Items
like ignition coils, temperature sensors, stepper motors and fuel
injectors all have a normal resistance.
You can use your multimeter to test these items to ensure they are working correctly in electrical terms.
You can find earthing problems, corroded connectors and other resistance problems using your meter in the resistance setting.
You can use your multimeter to test these items to ensure they are working correctly in electrical terms.
You can find earthing problems, corroded connectors and other resistance problems using your meter in the resistance setting.
Continuity
Continuity is used to
determine that the end of one wire is connected to the end of another
wire within a wiring system.
For example, you may need to check that a wire in the engine bay has "continuity" to a wire at the ECU.
Many meters have a beeper or buzzer to let you know that there is no resistance from one wire to another and hence that the two wires have continuity.
The beeper is extremely useful when working alone, as you often don't need to look at the meter when testing for continuity.
For example, you may need to check that a wire in the engine bay has "continuity" to a wire at the ECU.
Many meters have a beeper or buzzer to let you know that there is no resistance from one wire to another and hence that the two wires have continuity.
The beeper is extremely useful when working alone, as you often don't need to look at the meter when testing for continuity.