Idle Air Control Valve Replacement

Category: Auto Tuning

idle air control valve
Does your car idle rough or the speed cycle up and down. You probably have a bad idle air control valve. The only purpose of the idle air control valve is to keep the engine’s idle smooth. The engine’s computer gives the idle air control valve the feedback it needs to hold a constant rpm. The idle will be around 1000 rpm’s when not in gear and around 800 rpm’s in gear. This iac valve is on a Nissan Maxima and is similar to most idle air control valves.

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Clutch Slave Cylinder

Category: Auto Tuning

clutch slave cylinder
Rebuilding a clutch slave cylinder is sometimes needed after the clutch petal is no longer working. First you should check the clutch fluid container to verify it is full. If not follow the line down to the slave cylinder while looking for leaks to identify the problem. The clutch slave cylinder is located behind the passenger side wheel on this vehicle, a miata. Remove the two bolts and the clutch line and the slave cylinder should come off to the right side.

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Clutch Master Cylinder Rebuild

Category: Auto Tuning

clutch cylinder
If your clutch petal has ever lost pressure and the petal will not dis-engage the clutch, there is a leak. The leak may be air sucking in or fluid leaking out. First check the clutch fluid reserve, if it is low you will need to identify the leak. There should be a puddle of fluid at the leak. If a leaking line is not the culprit it may be the clutch master cylinder. If the clutch master cylinder or slave cylinder is faulty, there may be no loss of fluid. The clutch master cylinder is located on the firewall attached underneath the fluid reserve tank.

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Air Temp Sensor

Category: Auto Tuning

air temperature  sensor An air temperature sensor is used on fuel injected engines. The purpose of an air temperature sensor is to help the computer calculate air density. A change in temperature changes the resistance in the sensor. Simply stated, the higher the air temperature gets the less dense the air becomes. As the air becomes less dense the computer knows that it needs to lessen the fuel flow. If the fuel flow was not changed the engine would become rich, possibly losing power and consuming more fuel. The temp sender is generally located in the air inlet tube or the air box. The wire running to the sensor can be disconnected then the sensor can be unscrewed and replaced. Some aftermarket companies trick this sensor with a resistor (false temp reading) to make the engine run richer. If a engine has been tuned lean this trickery can show mild power gains.

Ignition Switch

Category: Auto Tuning

ignition switch location
Ignition switches are a common problem with cars. When an ignition switch dies, the engine will still spin over but will not start. The 12 volt power will never go to the ignition module to power the ignition coils. Ignition switches are similar on all cars and this procedure should work on most. This car is a sunfire and shares the same parts with a cavalier. First you will need to remove the three screws on the underside of the steering column cover.

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Cooling Fan Motor

Category: Auto Tuning

cooling fan
If a cooling fan will not turn on as the temperature reaches 200 degrees F, the fan motor may need to be replaced. To remove the fan on a 1995 Cadillac STS, start by removing the front plastic guard. Many other cars cooling fans are almost identicle to this set up and can be repaired in the same way. The plastic “trees” that hold the guard on will often break, so beware.

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Cooling Fan troubleshooting

Category: Auto Tuning

Cooling fans are easy to troubleshoot. Some automobiles use two smaller fans or one larger fan. The twin electric fan set up will use one fan for cooling the engine. The other fan will be used for cooling the air conditioning and radiator but only works with the ac on. Never continue to run the vehicle up in the red temp zone or you can cause severe damage to the engine. First do you have a temperature gauge in the dash? Is it working correctly? Lift the hood and verify visually that the fan is not working. Does the car cool down once you drive up the highway at 40+ mph? If not, you may have a thermostat sticking or low coolant. The thermostat can cause the engine to stay hot. This can also be the problem if the gauge stays low and the car never heats up. If the temp gauge is reading low yet the two radiator hoses are warm, the temp sensor may not be working. There may also be two temp sensors or senders, one that controls the gauge and one to switch the fan on. If the temperature is getting high and the fan still won’t come on you may have a fan problem.

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