posted info from a different site
"Here are some of the more common things I've seen with the CrossFire system.
· Coolant Sensor is faulty - the gauge gives a false sense that it's doing okay, but the sensor that the ECM reads is totally separate from the one the gauge reads! Pinging on acceleration during warmer runs are noticed. If in doubt, just replace the thing. The one the ECM reads is in the FRONT of the manifold - has two wires (black and yellow) going to it.
* Throttle Position Sensor is faulty; can give strange results. Bad idle, great high-RPM power. Always good idea to check this thing out. Uses a +5v reference to send voltage to the ECM. Neat trick: setup the output (center wire) to where it switches to full +5v with the flip of a switch. Makes the ECM think you're at full-throttle when you're not. (Good for acceleration with an automatic transmission, which is all the crossfires ever came with that I know of.)
* MAP sensor - this thing reads in the amount of manifold vacuum and sends out a voltage to the ECM. If it's not getting the correct voltage, you can get pinging real bad on acceleration at any temperature. Pull the wires off. If the idle improves, you have a faulty one. Replace it.
* Bad O-rings or filters on injectors. Turn the key, but don't start the motor. Have the air cleaner assembly off and observe the injectors. If they leak, replace the o-rings and injector filters. If they still leak, replace the injectors!
* Bad O2 sensor. Runs rich sometimes. Won't pass emissions for sure! Is suggested to replace every 30k miles or so. They cost around $25 and are a snap to replace. Not a bad idea to replace if you're going to get under the car in the first place. You can run a wire inside your car and read the voltage with a Digital volt meter to see what your air/fuel ratio is.
* Spark Plugs fouling.. often this is due to bad valve seals. One of my tricks is to uncover the plug electrode by "side gaping" the plugs.
* Knock Sensor.. I think this is my problem right now. The "Computer Codes" book said it causes light pinging during acceleration on light loads."
keep in mind that if you replace the stock tbi (throttle body injection) fuel pump in the tank is designed to work with a fuel pressure regulator and provide about 14 psi of pressure ,but they frequently produce less flow and pressure resulting in an engine that runs lean in the upper rpm ranges. if you replace it with a tpi fuel pump for the later tpi (tuned port injection) system those pumps produce approximately 40psi of fuel pressure but pressure is a measure of the resistance to flow that the fuel pressure regulator provides, you'll want to use an adjustable fuel pressure regulator and set it for about 16 psi if your using the TPI pump
"Here are some of the more common things I've seen with the CrossFire system.
· Coolant Sensor is faulty - the gauge gives a false sense that it's doing okay, but the sensor that the ECM reads is totally separate from the one the gauge reads! Pinging on acceleration during warmer runs are noticed. If in doubt, just replace the thing. The one the ECM reads is in the FRONT of the manifold - has two wires (black and yellow) going to it.
* Throttle Position Sensor is faulty; can give strange results. Bad idle, great high-RPM power. Always good idea to check this thing out. Uses a +5v reference to send voltage to the ECM. Neat trick: setup the output (center wire) to where it switches to full +5v with the flip of a switch. Makes the ECM think you're at full-throttle when you're not. (Good for acceleration with an automatic transmission, which is all the crossfires ever came with that I know of.)
* MAP sensor - this thing reads in the amount of manifold vacuum and sends out a voltage to the ECM. If it's not getting the correct voltage, you can get pinging real bad on acceleration at any temperature. Pull the wires off. If the idle improves, you have a faulty one. Replace it.
* Bad O-rings or filters on injectors. Turn the key, but don't start the motor. Have the air cleaner assembly off and observe the injectors. If they leak, replace the o-rings and injector filters. If they still leak, replace the injectors!
* Bad O2 sensor. Runs rich sometimes. Won't pass emissions for sure! Is suggested to replace every 30k miles or so. They cost around $25 and are a snap to replace. Not a bad idea to replace if you're going to get under the car in the first place. You can run a wire inside your car and read the voltage with a Digital volt meter to see what your air/fuel ratio is.
* Spark Plugs fouling.. often this is due to bad valve seals. One of my tricks is to uncover the plug electrode by "side gaping" the plugs.
* Knock Sensor.. I think this is my problem right now. The "Computer Codes" book said it causes light pinging during acceleration on light loads."
keep in mind that if you replace the stock tbi (throttle body injection) fuel pump in the tank is designed to work with a fuel pressure regulator and provide about 14 psi of pressure ,but they frequently produce less flow and pressure resulting in an engine that runs lean in the upper rpm ranges. if you replace it with a tpi fuel pump for the later tpi (tuned port injection) system those pumps produce approximately 40psi of fuel pressure but pressure is a measure of the resistance to flow that the fuel pressure regulator provides, you'll want to use an adjustable fuel pressure regulator and set it for about 16 psi if your using the TPI pump
