cylinder 3 misfire questions and what I've done so far

Do the cheap, easy and free tests first by doing a compression test and swapping injectors to see if the code follows. Not set on a head gasket issue but could also be valve related issue.You have to start with a compression test along with leak down test if it shows low compression.

 

You're on the right track

This..

Just the fact that #3 cylinder has a dry plug makes me suspect a bad injector. If you had fuel making it into cyl 3 and any other problem causing the misfire (lack of compression, no spark, etc) the plug would be wet

 

From the looks of it, it seems like swapping injectors is no quick task. I work as a fireman so my day is full of not being able to string more than 15-30 minutes together in a row.

 

I can't remember if number three injector is underneath the intake manifold or relatively exposed. If it's exposed, get a multimeter and compare its resistance to the other injectors. Also while it's running, put the metal tip of a stethoscope against it and compare the click sound it makes while operating to the others. There should be a fairly heavy tapping sound, if it's a lighter pitch than the others that could indicate that the pintle isn't opening fully

 

Sorry if someone said this, i just skimmed real quick, but did you change the coil pack on cylinder 3?
i had the same problem on cylinder 6 last month, and similar symptoms. changed the coil pack and all is well

 

Also maybe check the connector that plugs into coil pack 3, is it dirty or damaged?

 

Exhaust gas in the coolant system.
You can buy a test kit and test it yourself.
It’s easy enough to do.

I’m still going to stick with fuel delivery issue.
Especially if you haven’t experienced any coolant loss?

 

Wanted to close the loop on this. Ended up limping to the auto parts store (after stalling twice on the way) and got two ignition coils....figured what the hell. When I stopped (hadn't put on the new coils yet) I got out the code reader and checked to see if the code it was throwing yesterday had changed (cylinder 3 misfire). It said number 5 cylinder misfire. "What the hell?" I thought....I swapped coils yesterday between 3 and 5 and it was still reading "number 3 misfre" and the plug was still dry to confirm this. I was almost positive it was a bad injector because of how that test went.

I eagerly put a brand new coil on cylinder number 5 and started it up. Problem went away!! I then pulled the spark plug from cylinder 3 and it was now wet. I'm just spit-balling here...but I think that if a coil is bad and essentially is breaking the 'electrical loop" for that specific cylinder......the injector for that cylinder won't work? But now that the affected cylinder has a good coil, it essentially 'completes the circuit" and will now allow the injector to spray fuel?

I'm wondering if this is a built in fail-safe so if a coil or plug goes bad.....the cylinder won't load up with unburned fuel

 

hmm thats odd. usualy if the coil fails it sets a ignition coil circuit code. never pulled an plug with a bad coil and noticed dryness. but then again im not usually looking for that if i know its a coil.

could very well be something with the electrical system for the injectors and coils. but usually toyotas the injectors and coils share ground across all them

 

truck just misfired cylinder 3 and 5… no other codes and happened while driving…. So…. You think coils would be a safe places to start giving your experience with this?? I have 06 with 225000 miles original coils!