2000StreetRod
Moderator Emeritus
- Joined
- May 26, 2009
- Messages
- 10,597
- Reaction score
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- City, State
- Greenville, SC
- Year, Model & Trim Level
- 00 Sport FI, 03 Ltd V8
Problem:
Wideband Air/Fuel Ratio (AFR) meter displays >16:1 for Bank 2 (driver side) after M90 kit installation.
Background:
Prior to M90 installation AutoMeter 5978 Wideband Air/Fuel Ratio Monitor kit installed in Sept, 2009 worked fine. After installation of M90, vacuum/boost and custom tune (vehicle wasn't started for about 5 months during installation) and custom tune, the meter counts down for 20 seconds allowing for wideband sensor to heat and then displays maximum ratio of 16:1.
Troubleshooting
1.Tested all meter associated wiring for power, ground, opens and shorts to other wires.
2.Purchased new wideband O2 sensor and sensor connector to meter wiring harness. Replaced sensor.
3.Purchased new AutoMeter 5978 Wideband Air/Fuel Ratio Monitor kit and replaced meter in Bank2.
4.Removed old Bank2 wiring harness. Installed new meter kit in Bank1 and old meter with new wiring harness in Bank2 with common wiring except for O2 sensors. Bank1 worked normal, Bank2 same 16:1 display.
5.Swapped Bank1 and Bank2 meters - no change.
6.Logged STFTs with adaptive learning disabled. For cold start (ECT=64 deg F) Bank1 STFT begins cycling as soon as PCM switches from open to closed loop (10 seconds after engine start). Bank2 STFT switches to 0.70 (lean) at idle.
7.Reloaded PCM and logged STFTs with adaptive learning enabled. For cold start (ECT=74 deg F) Bank1 STFT begins cycling as soon as PCM switches from open to closed loop (10 seconds after engine start). Bank2 STFT switches to 0.70 at idle. At 3 minutes LTFT Bank2 starts increasing until it reaches 1.13. STFT Bank2 remains 0.70 until 4 minutes. During the first 4 minutes logged Fuel Pulsewidth in Clock Tics Bank2 are 1.6 times Fuel Pulsewidth in Clock Tics Bank1 - the opposite of what I expected. After 4 minutes (ECT=122 deg F) STFT Bank2 begins changing at a very slow rate and Bank1 and Bank2 pulse widths become comparable. At 5 minutes STFT Bank2 reverts to 0.70. At 7.6 minutes (ECT=146 deg F) increasing engine speed from idle to 1500 rpms had no effect on STFT Bank2. At 8 min engine speed was pulsed from 1500 to 2500 to 1200 rpms (PCM still in closed loop) causing LTFT Bank2 to change from 1.13 to 1.0 and STFT Bank2 to begin cycling and was identical to STFT Bank1 until the end of the log. Several throttle blips were performed causing wideband Bank1 meter to display AFRs as low as 10.5:1 but wideband Bank2 meter never read below 16:1.
8.Loaded latest tune into PCM, regapped cylinder 6 spark plug from 0.044" to 0.030" but did not connect plug wire. Started engine, waited for idle speed to stabilize and then connected plug wire. There was no audible detectable change in engine speed or stability. Repeated several times with same result. Spark detected on plug wire using timing light. Removed plug and performed compression test - 190 psi on warm engine. Installed new plug gapped to .030" - connecting and disconnecting plug wire makes no idle difference.
9. Attempted to listen to cylinder 6 injector using mechanic stethoscope but couldn't access the injector directly.
Plan
1.Disable IACV so cylinder not firing impact can be easily detected and then test each cylinder by disconnecting/reconnecting plug wires as plugs as regapped.
2.Remove wideband Bank2 O2 sensor and check for an obstruction in downpipe at bung.
3.Swap Bank1 and Bank2 wideband O2 sensors.
4.Hope for ideas from forum members.
Wideband Air/Fuel Ratio (AFR) meter displays >16:1 for Bank 2 (driver side) after M90 kit installation.
Background:
Prior to M90 installation AutoMeter 5978 Wideband Air/Fuel Ratio Monitor kit installed in Sept, 2009 worked fine. After installation of M90, vacuum/boost and custom tune (vehicle wasn't started for about 5 months during installation) and custom tune, the meter counts down for 20 seconds allowing for wideband sensor to heat and then displays maximum ratio of 16:1.
Troubleshooting
1.Tested all meter associated wiring for power, ground, opens and shorts to other wires.
2.Purchased new wideband O2 sensor and sensor connector to meter wiring harness. Replaced sensor.
3.Purchased new AutoMeter 5978 Wideband Air/Fuel Ratio Monitor kit and replaced meter in Bank2.
4.Removed old Bank2 wiring harness. Installed new meter kit in Bank1 and old meter with new wiring harness in Bank2 with common wiring except for O2 sensors. Bank1 worked normal, Bank2 same 16:1 display.
5.Swapped Bank1 and Bank2 meters - no change.
6.Logged STFTs with adaptive learning disabled. For cold start (ECT=64 deg F) Bank1 STFT begins cycling as soon as PCM switches from open to closed loop (10 seconds after engine start). Bank2 STFT switches to 0.70 (lean) at idle.
7.Reloaded PCM and logged STFTs with adaptive learning enabled. For cold start (ECT=74 deg F) Bank1 STFT begins cycling as soon as PCM switches from open to closed loop (10 seconds after engine start). Bank2 STFT switches to 0.70 at idle. At 3 minutes LTFT Bank2 starts increasing until it reaches 1.13. STFT Bank2 remains 0.70 until 4 minutes. During the first 4 minutes logged Fuel Pulsewidth in Clock Tics Bank2 are 1.6 times Fuel Pulsewidth in Clock Tics Bank1 - the opposite of what I expected. After 4 minutes (ECT=122 deg F) STFT Bank2 begins changing at a very slow rate and Bank1 and Bank2 pulse widths become comparable. At 5 minutes STFT Bank2 reverts to 0.70. At 7.6 minutes (ECT=146 deg F) increasing engine speed from idle to 1500 rpms had no effect on STFT Bank2. At 8 min engine speed was pulsed from 1500 to 2500 to 1200 rpms (PCM still in closed loop) causing LTFT Bank2 to change from 1.13 to 1.0 and STFT Bank2 to begin cycling and was identical to STFT Bank1 until the end of the log. Several throttle blips were performed causing wideband Bank1 meter to display AFRs as low as 10.5:1 but wideband Bank2 meter never read below 16:1.
8.Loaded latest tune into PCM, regapped cylinder 6 spark plug from 0.044" to 0.030" but did not connect plug wire. Started engine, waited for idle speed to stabilize and then connected plug wire. There was no audible detectable change in engine speed or stability. Repeated several times with same result. Spark detected on plug wire using timing light. Removed plug and performed compression test - 190 psi on warm engine. Installed new plug gapped to .030" - connecting and disconnecting plug wire makes no idle difference.
9. Attempted to listen to cylinder 6 injector using mechanic stethoscope but couldn't access the injector directly.
Plan
1.Disable IACV so cylinder not firing impact can be easily detected and then test each cylinder by disconnecting/reconnecting plug wires as plugs as regapped.
2.Remove wideband Bank2 O2 sensor and check for an obstruction in downpipe at bung.
3.Swap Bank1 and Bank2 wideband O2 sensors.
4.Hope for ideas from forum members.