Tempermental Cyl 2 Misfire 2.7l

I am having a misfire issue with my 2001 prerunner (california spec) w/ 223k miles. The CEL was throwing a P0302 so I assumed that since it is a high mileage truck and toyatas have a reputation for coils going bad that it was just a bad coil. I bought a new coil and replaced the old one and but it continues to misfire.

The unusual part about it is that the truck does not misfire when it is started after it has been cooled off completely. It will only misfire if you drive it to where you warm everything up then shut it off, let it cool for 15-20 mins and start it back.

After I replaced the coil and realized i still had a problem I swapped the coils between #1 and #2 to rule out getting a bad coil from the dealersip, cleared the CEL, started it and ran it (from cold) and it ran fine, but of course once I brought it back and let it cool for a little while the same misfire and P0302 code occur. My next idea to what it can be is the crank sensor?

Has anybody else had a similar problem or any suggestions?

Thanks in advance

 

I recommend a compression test. The video below has helped me greatly.


http://www.youtube.com/watch?v=g2_0bZG6UG4

 

You replaced the coil, but what about the plug wires and the plugs themselves?

 

I recently replaced the plugs 2k miles ago so they should all be fine, and I replaced the plug in the #2 cylinder a second time just in case the bad coil (or so i thought) had messed it up. I replaced them with OEM plugs.

Since my truck is the california spec it has 4 coils that sit directly on top of the plugs instead of 2 so there arent any plug wires, but all of the electrical connections to the coils are sound with no signs of corrosion.

If the fuel injector swap doesnt yield a result then I may just end up dropping it off with my mechanic since I'm running low on time to work on it. I was hoping for something simple but who knows I guess we'll find out.

 

While you do not have plug wires like the other types, there is still a boot and a coil type spring if memory serves, between the coil itself, and the plug. I would eliminate all ignition possibilities before digging into injectors or trying to test fuel pressure. It is the easiest system to test (ignition).

 

Sounds to me like the injector is leaking fuel into the cylinder while shutoff (after running for a while, and fuel rail is under pressure). When its completely cold, the fuel has had time to evaporate, and does not mis-fire.

Are you any getting black smoke when first starting up?

 

Problem has been solved (hopefully). We switched the #1 and #2 injectors and the problem followed to the #1 cylinder. So a new injector has been ordered and now we're just waiting for it to come in.

And to reply to tan4x4 I wasn't getting any black smoke at start up.

 

This is exactly what happen to me. The coils and plugs were the originals and in bad shape. I replaced them, and still had the miss fire just as you described. Thank you for posting this. I was scratching my head with this one.