"Misfire in Cyl. #3" Trouble Code

[bararonson]

Go back to the beginning of this thread an diagnose the same way. Switch coils, etc. Pull plug boots and look for arc paths. My daughters '97 ran rough, cyl.5 misfire. I pulled the plug boot and say the arc trails. Use dielectric grease, lightly on the largest diameters of the boot to keep out moisture.

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[St Runner]

Since you have the 2.7 I would get a compression check on all the cylinders too. Valves are known to get tight on the exhaust and a compression check would rule out a mechanical fault.

 

[infobesity]

Go back to the beginning of this thread an diagnose the same way. Switch coils, etc. Pull plug boots and look for arc paths. My daughters '97 ran rough, cyl.5 misfire. I pulled the plug boot and say the arc trails. Use dielectric grease, lightly on the largest diameters of the boot to keep out moisture.

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Can definitely check that off, didn't see any arcing trails on any of the boots when replacing the plugs (replaced boot+coil two weeks ago, replaced plug today). I'll definitely go through and see what other people did.

 

[nobb]

Misfires are definitely tricky! Listening to injectors is a start, but not 100% foolproof. I recently diagnosed a similar problem on a Ford Ranger. Thought the injector was fine after listening and doing a resistance check, so I replaced coils, wires, and plugs with no luck until I finally decided to replace the injector and that fixed it.

Does anyone know if our Toyota's have a "deep" OBD mode? Misfires only trigger a standard OBD code + check engine light if the misfires are severe enough. With my Ford, there was a "deeper" OBD function called Mode $06, of which I could get a real time count of the number of misfires since last engine start (through the Android Torque app). The misfires were not severe enough to trigger a CEL, but enough to read through Mode $06 to pin down which cylinder was problematic.

 

[infobesity]

Thanks for all the tips, currently I've replaced spark plugs, coil, boot, air filter, cleaned MAF sensor, replaced oil and oil filter for the hell of it, and dumped some BerryMan B12 Chemtool fuel injector/system cleaner into the gas tank and filled it up. Have yet to drive it around to get it through the injectors. Physically cleaning injectors or replacing them is my next step.

Still getting P0300 and P0302, Intermittent Random Misfire and Misfire on Piston 2.