I am curious about engine knocking when going up inclines. My 1990 V6 automatic 4x4runner starts knocking when I start an incline and I don’t know why. I have run injector cleaner through it and tried a higher octane gas. The spark plugs and wires have been replaced. Fuel and air filters are almost new, the knocking sound like the 4runner has bad gas, but I know it does not. Could this be the PCV valve? Also, when idling it sounds sort of like a diesel. Is this a related problem? Thanks for your feedback and help...

Is your check engine light on?
If it is, pull the error code(s). There are procedures for doing this in the sticky posts at the top of this forum.

What is your timing set to? This is set ONLY after the jumper is installed.

The knock sensor will detect the 8khz “knocking” caused by pre-ignition and sends a signal to the ECU and then the ECU retards the ignition to the point it stops.

A broken or faulty wire/knock sensor will result in a error code. But the ECU defaults to the retarded timing value if this happens.

The sound at idle might be your strongest indication that the timing is set WAY too far advanced. This can and will damage pistons and connecting rods in this motor. The rods are very soft and will warp slightly due to the pre-ignition pressures before top dead center.
Have someone familiar with the Toyota V6 timing procedure take a look at the setting. The sooner the better. Good luck.

The check engine light is not on. I am taking it to a buddies house to have the timing checked. Thanks for the info...

There is a jumper that needs top be installed while setting the timing.

Could you please explain how and where the jumper should be installed? Thanks for the feedback...

It was the timing! It was at about 15 degrees when I checked it. I set back to 10. The jumper information was under the hood, I should have looked first. For anyone trying to do this, I am by no means a mechanic and it was simple. It took about 5 minutes to complete.

WOO HOO!!! Good job!!
You'll notice alot more power on those hills with all the new ignition parts!
Spark plug gap is another critical setting that will make the difference in hard starting to gas mileage.

Good job!!