So, I've been having a problem with my 4-runner for a while. Starting the engine, and initial acceleration are good. When I get up to some higher speeds, 40+, I start to get some odd happenings.

As I accelerate to faster speeds, I will occationally get hesitations. I don't really know how to describe it accurately. It feels as if I'm pumping the accelerator to get a stuttered acceleration.

This past weekend, I went on a trip, and decided to use the next grade of gas. The issues got better. It's still there, but not as violent as it was before.

Any thoughts?

 

All right. Got some more information after going to the auto store. Hooked up the code reader. And with the code, P304. The understanding is that it's a problem with the firing of cylinder #4. What am I doing about it?

I'm going to replace the fuel filter. I don't expect this to fix this, but it certainly can't hurt.

I'm also going to use a bottle of fuel injection cleaner. Throw it in the tank, and see if that helps out. The thought of the guy at the store is that it's possible that there's a fuel injection problem with #4. Possibly a clogged injector.

Any other thoughts out there? Other things that I might want to look at as a next step, or as a concurrent step?

 

Change plug

 

check for oil on your plugs I had the same symptoms as you

 

Swap the plug into a different cylinder and swap the coil another different cylinder. Disconnect battery then drive until CEL comes back on. Have the code pulled again. If the misfire changes to a cylinder to the plug or coil that you put there is your culprit. If the misfire doesnt move you have an injector or compression issue

 

definitely something going on with that cylinder specifically so it should be easy to chase down the problem. inspect injector wires/ plug, spark plug, and spark plug wire to make sure everything is ok and nothing is obviously wrong. good call on the fuel filter and running some injector cleaner. its going to be an injector or ignition issue for sure