1. Warm-up engine to normal operating temperature.
2. Attach a timing light with advance indicator and a tachometer. Locate the Knock Control Sensor, (on the engine block), and ensure that the connector is secure.
See: LocationsSee Computer and Control, Knock Sensor, Location, Harness.
Fig. 210 Tachometer Hook-up
3. While operating the engine at 2,000 rpm, check the ignition spark advance and calibrate the timing mark to 0° TDC.
4. Using a wrench or small hammer, tap the exhaust manifold and observe the timing marks.
5. The ignition timing mark should move in the retard direction, depending on the intensity and speed of the tapping.
6. If the timing mark does not retard, turn the engine off and check the wiring between the Knock Control Sensor and the ECU.
7. If no problems are found, replace the Knock Control Sensor and repeat test procedure.
8. If timing still does not retard, replace the ECU.
9. Disconnect timing light and tachometer from the engine.
I did this test and could not get a responding retard spike. I noticed my advance on my timing light was around 40 deg to make it show at 0 deg on pulley. This was at 2000 rpm. This Toyota 22re runs a little uneven at idle(jumps from 750 to 740 to 760 rpm) and won't pass idle smog check. I have replaced the TPS in the past. My main interest is why does the timing not jump and if it doesn't why is there not a 12 code in the computer? What is the computer expecting to see from the knock sensor? Thanks
have the same problem?
Wednesday, June 18th, 2014 AT 8:04 PM