Geo Storm Isuzu Impulse Stylus FAQs

Home

Storm/Impulse Performance Parts

Solar and Alternate Energy

Storm Home - Mods - Specs - Research - Blog - History - Links - RTR Policies

Share |

Geo Storm, Isuzu Impulse/Stylus FAQs

Have a question that you can't seem to find about the Storm, Stylus, or Impulse? I hope this page will help you out!
this page is updated all the time...

Engine Related

Q: My car runs fine below 4000RPM, but as soon as I stomp on it, the car immediately starts to bog with no power.
A: when was the last time the Fuel filter was replaced? If the fuel filter is clogged, the engine is most likely getting enough fuel to start up and idle, but not enough fuel to get up in the higher RPMs where fuel requirements are greater. It is recommended that the fuel filter be replaced every 15,000 miles (every 1.5-2 years).

Q: I was driving one day and the car just died on me! What happenned?
A: There are a couple things to check:

You have gas in the tank, right? ;-)
Make sure the plug wires are all connected.
Ignition Module, this is located under the distributor cap. Costs about $30 to replace--they go out all the time.
Check to see if the timing belt snapped-it needs to be replaced every 60,000 miles. If it snapped, no worries, the isuzu engines are non-interference so no damage to the head/valves/pistons will take place.

Q: I am driving along and the Brake light and battery light came on at the same time, is that bad?
A: Yes, your alternator is going bad or has a bad connection. Take it to Autozone/Checker and they will check it for free.

Q: Uhh Ohh. I just got a "check engine light (CEL)". What does that mean?
A: If you get a CEL, that usually means that one of the sensors on the engine has signaled the ECM that there is a problem, or potential problem.
On the Geo Storm, Isuzu Impulse/Stylus/IMark RS, You can retrieve these error codes by "shorting" pins 1 and 3 the ALDL connector, it is located on the passenger side of the cabin, behind the kick plate on the right side. The ALDL connector is white and had 3 wires attached to it.

Take a paper clip and insert the ends into the two outside pins (pins one and three).

Turn the ignition key to the Accessory position, but do not start the car.

The gauge console should light up, and your CEL should be on.

Within a couple seconds, the CEL will start blinking the codes; "BLINK, BLINK-BLINK" would be a code 12.

The ECM will blink the code 12 three times, then start spitting out the other codes.
Here is a list of all the codes and their definition:

Trouble Code	Name of Code and potential fix
12	Engine is off, Diagnostic system is working. This code will display at the beginning and end of the scan cycle when the computer is functioning normally. If this code will not display, check the power and ground to the ECM.
13	Oxygen Sensor - Open or Grounded Circuit Indicates a problem with the reading reported by the Oxygen Sensor. Check the wires and connectors between the ECM and the Oxygen Sensor. Check the Oxygen Sensor itself. The easiest way to check if the sensor is functioning is with the Tech-1 scan tool. Start the engine, set the scan tool to indicate if the computer is in Open Loop or Closed Loop mode. Allow the engine to warm up for 5 minutes. If the sensor is functioning, the computer will got from Open Loop to Closed Loop operation mode when the water temperature and exhaust manifold reach normal operating temperatures.
14 A	Coolant Temperature Sensor Circuit - High Temperature Indicated Indicates that the ECM believes the CTS has failed and is reporting a high temperature reading regardless of actual temperature. Check the wires and connectors between the ECM and the Coolant Temperature Sensor. Check the resistance of the sensor with a multi-meter and verify that it is showing high resistance when it is cold, or bring up the CTS reading on the Tech-1 scan tool and compare the temperature reading to what would be expected for the ambient temperature and engine temperature.
14 B	Coolant Temperature Sensor Circuit - Low Temperature Indicated Indicates that the ECM believes the CTS has failed and is reporting a low temperature reading regardless of actual temperature. Check the wires and connectors between the ECM and the Coolant Temperature Sensor. Check the resistance of the sensor with a multi-meter and verify that it is showing low resistance when it is warm, or bring up the CTS reading on the Tech-1 scan tool and compare the temperature reading to what would be expected for the ambient temperature and engine temperature.
21 A	Throttle Position Sensor Circuit - Voltage Signal High Indicates that the ECM believes the TPS has failed and is reporting a high voltage reading regardless of the actual throttle position. Check the wires and connectors between the ECM and the Throttle Position Sensor. Checking the sensor requires the use of the Tech-1 scan tool. Set the scan tool to show TPS voltage and position. Move the gas pedal and/or throttle arm on the throttle body, and verify that the sensor reading changes with the throttle position.
21 B	Throttle Position Sensor Circuit - Voltage Signal Low Indicates that the ECM believes the TPS has failed and is reporting a low voltage reading regardless of the actual throttle position. Check the wires and connectors between the ECM and the Throttle Position Sensor. Checking the sensor requires the use of the Tech-1 scan tool. Set the scan tool to show TPS voltage and position. Move the gas pedal and/or throttle arm on the throttle body, and verify that the sensor reading changes with the throttle position.
23 A	Intake (Manifold) Air Temperature Sensor Circuit - Low Temperature Indicated Indicates that the ECM believes the IAT Thermistor has failed and is reporting a high temperature reading regardless of actual temperature. Check the wires and connectors between the ECM and the Intake Air Temperature sensor. Check the resistance of the sensor with a multi-meter and verify that it is showing high resistance when it is cold, or bring up the IAT reading on the Tech-1 scan tool and compare the temperature reading to what would be expected for the ambient temperature and engine temperature.
23 B	Intake (Manifold) Air Temperature Sensor Circuit - High Temperature Indicated Indicates that the ECM believes the IAT Thermistor has failed and is reporting a low temperature reading regardless of actual temperature. Check the wires and connectors between the ECM and the Intake Air Temperature sensor. Check the resistance of the sensor with a multi-meter and verify that it is showing low resistance when it is warm, or bring up the IAT reading on the Tech-1 scan tool and compare the temperature reading to what would be expected for the ambient temperature and engine temperature.
24	Vehicle Speed Sensor Circuit This Trouble Code will register when the ECM notices the engine is running above idle speed for an extended period of time, and the VSS (located in the speedometer mechanism) is not registering any vehicle speed. Check the wires and connectors between the instrument cluster (Vehicle Speed Sensor) and the ECM. Check the speedometer cable connection at the transmission and at the speedometer. Make sure the cable itself is not broken. This Trouble Code is most commonly seen if the vehicle is operated with a broken or disconnected speedometer cable.
32	Exhaust Gas Recirculation Circuit - California Emissions Indicates a problem with the reading reported by the temperature sensor installed in the EGR valve for vehicles equipped with California Emissions. The computer wants to see a different temperature reading when the EGR valve is open, and when the EGR valve is closed. This would indicate when exhaust gas is flowing through the valve and the valve is functioning properly. Check the function of the valve. Check the function of the transducers in the vacuum system. Check for water accumulated in the vacuum lines and/or rust inside the EGR diaphragm. Check for blockage of the EGR pipe and/or passages in the intake manifold behind the EGR valve. Check the sensor connector, wires, and output readings. This Trouble Code will often display when there is no problem with the EGR system. When the intake manifold and EGR valve assembly reach operating temperature, the temperature sensor will start reporting a steady reading, the temperature of the manifold and valve assembly itself, and not the temperature of air passing through the valve assembly. This is due to normal heat absorption of the metal assembly (heat soak).
33 A	Manifold Absolute Pressure Sensor Circuit - Signal Voltage High - Low Vacuum Indicates that the ECM believes the MAP sensor has failed and is reporting a low vacuum reading regardless of actual pressure. Check the hose and hose connections between the Manifold Absolute Pressure sensor and the intake manifold. Check the wire and connecters between the Manifold Absolute Pressure sensor and the ECM. Checking the sensor requires the use of the Tech-1 scan tool. Set the scan tool to show MAP voltage and reading. Check the reading before starting the engine and make sure it is close to the local barometric pressure. Start the engine, rev the engine lightly, and make sure the sensor reading shows high vacuum at idle with the engine running, and when the throttle is opened, that the vacuum drops almost to the reading before the engine was started.
33 B	Manifold Absolute Pressure Sensor Circuit - Signal Voltage Low - High Vacuum Indicates that the ECM believes the MAP sensor has failed and is reporting a high vacuum reading regardless of actual pressure. Check the hose and hose connections between the Manifold Absolute Pressure sensor and the intake manifold. Check the wire and connecters between the Manifold Absolute Pressure sensor and the ECM. Checking the sensor requires the use of the Tech-1 scan tool. Set the scan tool to show MAP voltage and reading. Check the reading before starting the engine and make sure it is close to the local barometric pressure. Start the engine, rev the engine lightly, and make sure the sensor reading shows high vacuum at idle with the engine running, and when the throttle is opened, that the vacuum drops almost to the reading before the engine was started.
42	Electronic Spark Timing Circuit Specific to 1992-93 models only. Indicates that the ECM believes the Ignition Module has failed. Check the wires and connectors between the Distributor and the ECM.
44	Oxygen Sensor Circuit - Lean Exhaust Indicated Indicates that the ECM believes the O2 sensor has failed and is reporting a lean fuel mixture reading regardless of actual condition. Check the wires and connectors between the ECM and the Oxygen Sensor. Checking the sensor requires the use of the Tech-1 scan tool. Bring the vehicle up to operating temperature and wait for the ECM to go into Closed Loop mode. Set the scan tool to read the O2 sensor reading. The normal reading will jump to the extremes of rich and lean repeatedly (100-900 ohm). This will indicate that the computer is constantly adjusting the gasoline flowing through the injectors, and that the sensor is constantly reading the adjustments. If the sensor reading is constantly at one end of the range or the other, a problem is indicated. Usually a sensor failure and the sensor is no longer able to read the full range of measurement.
45	Oxygen Sensor Circuit - Rich Exhaust Indicated Indicates that the ECM believes the O2 sensor has failed and is reporting a rich fuel mixture reading regardless of actual condition. Check the wires and connectors between the ECM and the Oxygen Sensor. Checking the sensor requires the use of the Tech-1 scan tool. Bring the vehicle up to operating temperature and wait for the ECM to go into Closed Loop mode. Set the scan tool to read the O2 sensor reading. The normal reading will jump to the extremes of rich and lean repeatedly (100-900 ohm). This will indicate that the computer is constantly adjusting the gasoline flowing through the injectors, and that the sensor is constantly reading the adjustments. If the sensor reading is constantly at one end of the range or the other, a problem is indicated. Usually a sensor failure and the sensor is no longer able to read the full range of measurement.
51	ECM Failure Indicates that the ECM has failed, or the EPROM within the ECM has failed. Check the electrical connections for the ECM. If code persists, the ECM requires replacement.

Suspension Related

Q: My car is really bouncy, do I need new springs?
A:No, that is a sign that your springs are still good, but your Struts are blown. You have a couple choices:

Gabriel - A good, low cost strut if you are low on cash. Has stock dampening capability
Monroe - Another good replacement strut with stock dampening capability. Sears sells these!
Factory replacements - If you can afford these, can I have a grant? ;-) Actually, these are KYB struts built for Isuzu. Very nice struts.
KYB GR2 - The best performance related strut. More expensive than the first 2 listed, but well worth the extra cash, IMO.

Since you are replacing Struts, you might as well replace the strut mounts. Any brand will do from what I have seen. The way you can tell if the mounts are bad is by looking at the top of them. if they are all cracked up, or if they are making a CLUNK sound over bumps, they are bad.
It is STRONGLY recomended that you replace the Struts and mounts if you are installing Coilovers. If the struts/mounts are bad, you will be in for one extremely bumpity ride.

Transmission/Axle/CV Related

Q: I looked under the car and noticed grease splattered all over the place in the wheel well and brake/axle. What happenned?
A: The CV boot cracked/tore! Time to get it fixed before all the grease spills out, dirt get in and the joint goes bad. A new boot costs ~$10. You have to remove the axle to replace it, unless you have the cool tools to do it all on the car. If not, it would be a good time to replace the Transmission Output Shaft seals while you are there ($5-$7 each-one per axle)

Q: My Axle/wheel makes a clicking noise whe I make a turn, what is it?

A: This is a sure sign that the CV joint is bad/going bad. It is easier to replace the whole axle than to just replace the joint. It would be a good time to replace the Transmission Output Shaft seals while you are there ($5-$7 each-one per axle)

Q: Ok Smart guy, I replaced the axle like you said and all the manual tranny fluid poured out all over the floor! What do I replace it with?
A: 5w30 motor oil! 80-90 weight oil is used in those really old trannys-not in your Isuzu tranny! (~1.7qts) Use kitty litter to clean up the oil spill. Captain Hazelwood said so! ;-)

Geo Storm isuzu impulse performance parts