I am thinking this may be related to the IGF signal going to from ECU. I didn't notice if there was one on the other side of engine block.
Not sure if the 1ZZ engine w VVTi has this tho, and why it would even run if its not attached, unless it is just triggering by being near the coilpacks. It seems no signal shuts down fuel delivery. maybe it's a G signal sensor?
"
The
IGf signal is generated by the igniter on EFI/TCCS systems. The ECU supplies a 5 volt reference through a pull-up resistor to the
lGf signal generation circuit in the igniter. When a spark plug fires, the IGf signal generation circuit pulls the five volts to ground, causing a pulse to be sensed at the ECU. One pulse is generated by the igniter for each ignition event which is carried out.
The IGf signal confirms that ignition has actually occurred. In the event of a failure to trigger an ignition event, the ECU will shut down injector pulses to protect the catalyst from flooding with raw fuel. Typically this failsafe shutdown occurs within eight to eleven IGt signals after the IGf signal is lost. This condition can occur with any primary ignition system fault, an igniter failure, a problem with the IGf circuit wiring, or with a faulty ECU."
"
There are three signals which are necessary to operate the fuel injectors. These are the Ne, G, and
IGf signals. Inside the ECU, the
Ne Signal is used to produce an injection chive signal. The
G signal is used to determine the timing of the injection signals. The IGf signal is monitored for fuel delivery fail-safe. (With Conventional EFI, the IG signal is used to produce the injection drive signal.)
The ECU cannot pulse the injector without an Ne signal and will not start or run if this signal is not present. If the G signal is not present while cranking the engine, the ECU will not be able to identify when to produce the injection signal. The result will be the same, no injection pulse. If the IGf signal is not present, the ECU will go into fuel fail-safe by stopping injection pulses.
If, however, the ECU loses the G signal with the engine running, the engine will continue to run because the timing of injection signals is locked in once the engine starts."
LGf Signal - Toyota Engine Control Systems - Toyota Service Blog
edit:
Engine running fine, But getting some detonation every 4-5 seconds, irregularly, only notice it at idle, or stoplight. Have done most of the "Readiness Drive Monitor" but not the long drive or the temp set.
I have both up and downstream O2 sensors disconnected, (for a year now) because of the firmware bug of the 45deg temp swing between coolant sensor, and exterior temp sensor.
Same gas mileage in city, and just a bit more oil use.
