P0301 2000 Tacoma 3RZ-FE Cylinder 1 Misfire Rough Idle No Power

Hey All,

I've read through all the other threads on this topic but still having issues.

I have a 2000 Tacoma 2.7 3RZ that upon starting up suddenly started idling very rough and has no power. CEL Blinking and get P0301 code, Cylinder 1 Misfire.

Here is what I have tried:
- Compression Tested Cylinder 1 : 160 PSI
- Replaced Spark Plugs - Cylinder 1 was blackened and diode was gone. Cylinder 3 also bad.
- Resistance Tested Coil Packs - Both around 12.9 Ohms within normal range.
- Tested resistance on spark plug cables.
- Moved the Fuel Injector from Cylinder 2 to Cylinder 1. No difference. I think injectors are ok.
- When Fuel Injector for cylinder 1 is disconnected engine runs more smoothly, when reconnected engine sputters like the cylinder is mostly misfiring.
- Inspected Fuel Injection wiring and couldn't find anything obvious.

Other info:
My catalytic converter failed 4000 mi ago, and I don't currently have one. Valves are long overdue for an adjustment. Tail pipe is black and gas mileage hasn't been great.

Any tips/ Ideas?

Thanks!

 

Based on your description and tests I suspect the control wire for injector 1 may be shorted to ground.

Test light connected to battery positive unplug the number 1 injector and touch Pin 1 (White/Red) of the connector, with the engine idling the light should be flashing. If it is on steady then either the wire is shorted to ground or the driver in the PCM is bad.

 

I found out the weakest part of your ignition system is the switch....

My bad switch would start the truck.....but would stutter, lack power...like it wasnt getting gas......
And after getting hot after awhile.....blown 30a am2 fuse.....
would blow as you take off from a green light......

Let cool down couple hours.....new fuse and starts right up again......



I know thats not your problem.....but a brown out past that switch could effect different systems........a lot of stuff goes thru that switch....powers ecm, dash, fuel pump, injectors, coils, ect.....

 

Thanks for this. I dont have a light, but was trying to test it with a multimeter. I couldn't tell much of a difference between cylinder 1 and 2 this way. I saw in another thread that you can check continuity of the control wire, but am a little confused on how to do that with a multimeter.

 

With the car in On position (engine off) I get a consistent 12 V in the B-R Ground wire to cylinder 1 fuel injector.
With the engine idling and a multimeter between the W-R wire on the fuel injector circuit and positive battery terminal I am getting a pulsing voltage reading. Cyl 2 seems to show similar readings to cylinder 1.

 

A test light would be better to use to check power and control than a meter, they can be easily found at any auto parts store and most stores with an automotive section.

Have you swapped the coil and checked if the miss follows it?

 

Did you figure out the issue

 

This is a 3 year old post and having said that there is a possible misdiagnosis. Does toyota incorpate this stragey in their PCM, dont know, I would have to check the truck while it is running. When the Check Engine light flashes that is the PCM telling you stop, you are doing damage and in an attempt to prevent damage the PCM will shut off that injector. You swap injectors and you think that you have 2 bad injectors and/or you continue down a path based on a misdiagnosis.