Mysterious misfire

2004 Tacoma v6 auto

throwing a cylinder 5 misfire. Did new plugs,injectors and wires, compression was fine

the weird part about the entire misfire is it only happens when I hit 80km/hr or 49miles but when I have overdrive turned off there is no misfire. No matter the RPM. Any ideas are appreciated

 

Been thinking about this post for a couple of days. Was it misfiring before you changed the coils? Switch coils if it didn't and see if it travels to another cylinder. If this does not work (the tranny has nothing to do with it) I would guess it's a ECU problem.

 

Only replaced the coils because of the issue haha. Didn’t think ecu. I know buddy has a few laying around maybe that’s the next attempt!

 

I have a random misfire and a crappy idle. I have bought a TPS, but haven’t taken the time to put it on yet. That could be your issue too. I’ve went through the whole plugs, wires, MAF, coils, throttle body troubleshooting process. If it’s not the TPS, it’s sounding like a cam or crank sensor on mine. Could be something similar for you as well if the spare ecu swap doesn’t fix it.

Not sure if you’re familiar with the fiasco that Toyota is with the TPS, but there’s some good threads on here if you search around. I’m going to have to search around for them myself when I go to change it.

I have a huge write up I was going to post a while back after I put the TPS in… need to get it in and post that write up if it fixes it.