Let's find that lost cylinder 5 out of 6 ain't bad right

Replace that boot at the air box. Any leak of air into it will cause issues.

 

So took the 04 parts truck out again to see if I can figure out what's going on.


Took off spark plug caps and idle did not change when #3 & 6 were removed. I then took 1 & 4 and switched with #3&6 and changed the plug from the wiring Harnis that connects to the coil. No change I am confident that all coils are producing spark.

 

Clared codes and ran with coils switched until the CEL came back on.
031
0300
0306
0303

 

Same codes as I pulled in post #5 !

 

Does anyone know if the plugs from the wiring harnesses are going to the right coil ?

 

Noticed something else not sure if it's related but there are no hoses on this hard line. Anyone know what that line is for ?

 

Last thought ?

If the coil is good and it's getting spark and I move onto injectors
Why would two injectors fail on different banks that are fed by the same coil. Weird ?

What if anything can I do to test the computer ?

 

Your coil plug should be correct. They're not design to reach one cylinder to the next. And if somehow magic occurred and do reach, your vehicle will not run at all. Will be firing at wrong tdc/bdc stroke.

Try this to verify spark.

First: pull fuel pump reply/fuse

Second: Pull the spark plug out from both cylinder 3&6. Leave coil plug into harness and leave it dangling on side of cylinder head, same with spark plug wire. push both spark plug into wire and boot. One person crank the car, another person verify both spark plugs are sparking

If spark is present, rent a compression tool from your local auto part store to verify cylinder compression.

My experience with p0300 with toyota usually end with timing belt jumping a tooth or two, off align cam pulley to crank, or crack cylinder head. I would say the 3.4 is known for it, crack usually occur between thread for plug to valve. I call it, "the flash of death" from mil light.

 

Black/red wire at harness connector should go to ground. Check all three for comparison. Should go to fastener somewhere close by.

 

have you tried having your injectors cleaned out?

 

Idle's fine, no power under load; most likely ECU pulling timing. Could be carbon build up in cylinders causing detonation.

Also check your cat converter to make sure its not clogged. Won't cause the misfire but will cause power to drop under load.

Get your oil analyzed for coolant to make sure you don't have a blown head gasket. Could cause misfires, etc...

Good luck!

 

Jon G,

V5ensx brings up an interesting point that one of your heads could be cracked. The only thing that makes his point unlikely is that the truck from what you said has 148,xxx miles on it, which is not many miles for a non-abused Toyota 3.4. The reason his theory of a cracked head might be the culprit is if this truck has been badly abused and the engine has not been well maintained, which certainly could be the case since it was not running on all of its six cylinders since you got it. A compression test on all cylinders will tell you what shape this motor is in.

Good Luck,
Paul

 

Picture 2 & 6 are of the two of the cylinders that are missing. Done with a princess auto compression testor

 

Haven't heard any mention of the igniter. It fires the 3 coils under direction of the ECU. It has among other things, 3 circuits. One for each coil. Check for wire, connector, connector pin problems and the ground connection. Hard for a shade tree to test them further and they are costly. Fortunately your 02 and 04 use the same part number. Swap them and cross your fingers.

Location (on a 99), red arrow.

 

Jon,

I admire your diligence and patience in your attempts to repair your 2002 Tacoma.

Take it easy,
Paul

 

v5nsx I took a extra plug and stuck it in the boot of 3&6 fired the truck up. Lots of spark
Second picture flash was on but can't see the spark

Thanks for the replys everyone lots of good advice !

 

No injector cleaning yet need to research how and what to use

Thanks for the reply !

 

Thanks for the reply !

The previous owner said he brought it to a few mechanics (backyard) and he was told there was a wire coming from the ecu that had no power. I wanted to cover all my basis before I track down a ecu

 

BG make some very good cleaner...

I doubt it's clogged injector. If two cylinder is running lean, your wideband afr sensor should trigger a p0171.