95 NSX T new cats are installed but problem prevails.............
Parts installed:
4 new O2 sensors
New PCV valve
New plugs
New coils
New timing belt
New thermostat
New cats
New fuel filter
New fuel pump
Removing the old cats I was very disapointed to see that they were still good with no damage or clogging.
Cleaned and replaced the battery and engine grounds with gold terminals soldered onto new copper cables. Installed the new converters and O2 sensors and ran my car, code 64 went away and the check engine light and relay click problem went away. The grounds improved the cold running hesitation but did not eliminate the problem. When cold, you have to drive 100 yards or so then it has full power and no problems until you park and restart the car. When starting hot, the problem may last 100 feet or might not happen at all and car drives normally, bizarre eh? This emission problem is really getting to me, failed again! I’m now a certified California Gross Polluter! This car has the original 95 engine wire harness and intake manifold that was taken off the engine that was sold from the car. It’s all original parts as far as the harness and sensors are concerned, only the long block was changed. Someone mentioned that there is an internal ground that can go bad inside of the ECU itself. Not sure what to try next, have replaced a lot of parts with little results to fix the original problem. The plugs are beautiful grey and the exhaust smells sweet. Maybe the ECU is bad? should I buy a spare and try that? Will have to try other things I guess, running out of ideas. Below is today’s smog test and it is slightly better but still far away from passing.
Test date 11/17/10
Test _______ Rpm |%CO2|%O2| HC (PPM) | CO (%) |
_M1: 15 mph 2678 | 10.7 | 0.0 | MAX 85 Meas 261 | MAX 0.50 Meas 6.78|
_M2: 25 mph 2427 | 10.5 | 0.0 | MAX 50 Meas 275 | MAX 0.47 Meas 7.15|
Test date 09/13/10
Test _______ Rpm |%CO2|%O2| HC (PPM) | CO (%) |
_M1: 15 mph 2611 | 9.8 | 0.1 | MAX 85 Meas 296 | MAX 0.50 Meas 7.57|
_M2: 25 mph 2427 | 9.4 | 0.0 | MAX 50 Meas 303 | MAX 0.47 Meas 8.03|
Original thread
95T running too rich, no ECU codes
--------------------------------------------------------------------------------
UPDATE:
Finaly got a code that makes sense out of the ECU besides the engine misfire ones. Code 64 is indicating that rear secondary O2 sensor has a problem and is not working. Would that make the car run erratic power cold and put the car in failsafe or limp mode?
The exhaust is very black too which shows cats aren't working fully. They are at temps of 512 and 479 degrees after a six mile highway run, seems too cold for good running cats. The cats are from the 1990 engine installed in this car. The secondary O2 sensors are resistors and O2 simulater units. Guess it's time for Pro Speed converters with bungs installed for real secondary O2 sensors.
I have just completed my five year project 1995 NSX T and putting the car on the road. First problem was gelled gas from sitting which destroyed the original fuel pump and another replacement pump in the tank. Cleaned tank out and replaced pump and gas, put some carb cleaner in fuel rail and ran the car. The car has power and idles and accelerates fine when hot. Problem is no power when accelerating cold, super lean, pops in intake manifold. When the engine warms up the problem suddenly goes away and check engine light comes on. Stored code is 71,72,73,74,75 and 76 "cylinder misfire". If you reset the ECU (pull clock fuse) and drive the car hot it drives fine and no codes are stored in the ECU. When getting the car smoged for registration, HC and CO2 are off the scale! needless to say it fails, here are the readings:
Test ______Rpm|%CO2|%O2|___ HC (PPM)___ | CO (%) |
_M1: 15 mph 2611 9.8 | 0.1 | MAX 85 Meas 296 | MAX 0.50 Meas 7.57|
_M2: 25 mph 2427 9.4 | 0.0 | MAX 50 Meas 303 | MAX 0.47 Meas 8.03|
I was wondering what to do because there are no codes to go by, bad injectors? Any sugestions?
Did some experiments today. Measured the cluster temperature sensor cold and hot, it is within specs. When starting the car cold it turns over and starts in 3 seconds and idles smooth. When pushing the accelerator pedal the rpm drops down and if you push it all the way the car will almost stall running extremely lean. After about 3 minutes you hear a click like a relay sound, check engine light comes on at the same second, then car accelerates normal with full power and no problems other than running rich for emissions. I’ll have to get a fuel pressure gauge to see what’s going on as a baseline.
Stephen
Parts installed:
4 new O2 sensors
New PCV valve
New plugs
New coils
New timing belt
New thermostat
New cats
New fuel filter
New fuel pump
Removing the old cats I was very disapointed to see that they were still good with no damage or clogging.
Cleaned and replaced the battery and engine grounds with gold terminals soldered onto new copper cables. Installed the new converters and O2 sensors and ran my car, code 64 went away and the check engine light and relay click problem went away. The grounds improved the cold running hesitation but did not eliminate the problem. When cold, you have to drive 100 yards or so then it has full power and no problems until you park and restart the car. When starting hot, the problem may last 100 feet or might not happen at all and car drives normally, bizarre eh? This emission problem is really getting to me, failed again! I’m now a certified California Gross Polluter! This car has the original 95 engine wire harness and intake manifold that was taken off the engine that was sold from the car. It’s all original parts as far as the harness and sensors are concerned, only the long block was changed. Someone mentioned that there is an internal ground that can go bad inside of the ECU itself. Not sure what to try next, have replaced a lot of parts with little results to fix the original problem. The plugs are beautiful grey and the exhaust smells sweet. Maybe the ECU is bad? should I buy a spare and try that? Will have to try other things I guess, running out of ideas. Below is today’s smog test and it is slightly better but still far away from passing.
Test date 11/17/10
Test _______ Rpm |%CO2|%O2| HC (PPM) | CO (%) |
_M1: 15 mph 2678 | 10.7 | 0.0 | MAX 85 Meas 261 | MAX 0.50 Meas 6.78|
_M2: 25 mph 2427 | 10.5 | 0.0 | MAX 50 Meas 275 | MAX 0.47 Meas 7.15|
Test date 09/13/10
Test _______ Rpm |%CO2|%O2| HC (PPM) | CO (%) |
_M1: 15 mph 2611 | 9.8 | 0.1 | MAX 85 Meas 296 | MAX 0.50 Meas 7.57|
_M2: 25 mph 2427 | 9.4 | 0.0 | MAX 50 Meas 303 | MAX 0.47 Meas 8.03|
Original thread
95T running too rich, no ECU codes
--------------------------------------------------------------------------------
UPDATE:
Finaly got a code that makes sense out of the ECU besides the engine misfire ones. Code 64 is indicating that rear secondary O2 sensor has a problem and is not working. Would that make the car run erratic power cold and put the car in failsafe or limp mode?
The exhaust is very black too which shows cats aren't working fully. They are at temps of 512 and 479 degrees after a six mile highway run, seems too cold for good running cats. The cats are from the 1990 engine installed in this car. The secondary O2 sensors are resistors and O2 simulater units. Guess it's time for Pro Speed converters with bungs installed for real secondary O2 sensors.
I have just completed my five year project 1995 NSX T and putting the car on the road. First problem was gelled gas from sitting which destroyed the original fuel pump and another replacement pump in the tank. Cleaned tank out and replaced pump and gas, put some carb cleaner in fuel rail and ran the car. The car has power and idles and accelerates fine when hot. Problem is no power when accelerating cold, super lean, pops in intake manifold. When the engine warms up the problem suddenly goes away and check engine light comes on. Stored code is 71,72,73,74,75 and 76 "cylinder misfire". If you reset the ECU (pull clock fuse) and drive the car hot it drives fine and no codes are stored in the ECU. When getting the car smoged for registration, HC and CO2 are off the scale! needless to say it fails, here are the readings:
Test ______Rpm|%CO2|%O2|___ HC (PPM)___ | CO (%) |
_M1: 15 mph 2611 9.8 | 0.1 | MAX 85 Meas 296 | MAX 0.50 Meas 7.57|
_M2: 25 mph 2427 9.4 | 0.0 | MAX 50 Meas 303 | MAX 0.47 Meas 8.03|
I was wondering what to do because there are no codes to go by, bad injectors? Any sugestions?
Did some experiments today. Measured the cluster temperature sensor cold and hot, it is within specs. When starting the car cold it turns over and starts in 3 seconds and idles smooth. When pushing the accelerator pedal the rpm drops down and if you push it all the way the car will almost stall running extremely lean. After about 3 minutes you hear a click like a relay sound, check engine light comes on at the same second, then car accelerates normal with full power and no problems other than running rich for emissions. I’ll have to get a fuel pressure gauge to see what’s going on as a baseline.
Stephen
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