Here's my dilemma I been fighting the last two weeks or so after I converted my 96' to the later year MAF. Long story short, I have a 96' V-6 model, all maintenance done from timing belt to all the fluid change. Truck been throwing the same code (P0306) basically Cylinder 6 mis-fire detected. I change to new oem wires and got new plugs. The problem went away for a week and came back (again).

After swapping coils, thinking maybe it's the coil. No luck, swap coils with buddy Tacoma. Same deal. I finally took off the upper timing cover and see there is a cam angle sensor. Sensor doesn't look like the hall effect type. Look like the old skool magnet and trigger style. When resetting the ECU with a logger. Truck will run fine for 10 or so minutes before sputtering and engine will shake like it have a bad case of Parkinson disease. Then the CEL will flash about 13 times and stay on. If I shut the truck off and wait a minute or so. Start it back up and then it runs fine. I have a feeling the ECU sense there is a mis-fire in cylinder 6. But when I pull the plug out, everything seem fine. No black sooty deposit or metal speckles (from detonation). With the CEL on, I unplug the cam angle sensor and truck still start. My question is how does the ECU know that cylinder 6 is knocking other than timing from the crank and cam. I know with certain cars once it's running you can pretty much unplug it and it will still run, but with it unplug vehicle will not start.

Does the ECU see the mis-fire from the knock sensor? And if so where is the knock sensor located? Is there one or two knock sensor? I know it's more accurate for manufacture to use the crank timing for timing and controlling the injectors. Does anyone here know if the ECU pulls signal from the cam angle sensor and use that to give timing?

I already tried swapping ignitor with another 4-Runner and same luck (or lack of). I know magnetic base sensor are very relible and usually don't go out and not affected by heat. But anyone here had one gone bad on them before? I'm about to bust out the ocilloscope and check out the signal it's spitting out.

Thanks

 

no, the ecu detects misfires by monitoring crankshaft acceleration and deceleration, when a cyl fires the ecu looks for a slight increase in rpm, if it does not see the increase, then it will record that a cyl is misfiring and set a code