Hello I have a 94 Toy 4x4 22RE. It is making extremely loud tapping noise when I first apply gas and goes away if I am full throttle, the ping comes back if I let up on the throttle and goes away if just idling.
I was prepared to do a valve adjustment but, I almost believe my timing chain is causing the noise. Do you all have any suggestions? I am going to try to find a stethoscope to pin point the noise.

>>>*Hi. You almost answered your own question, this does sound like pinging.

Back the ignition timing off one degree and see if it changes to less ping. If it doesn't, try loosening the valve lash just .001" on all of them. This effectively retards the valve timing slightly and can reduce pre-ignition.

If that doesn't cure all or most of it, then try a cooler range spark plug, this is usually a last resort..

Note that a plugged or inoperative EGR valve or port can cause pinging, the lack of introduction of unburned gasses containing low oxygen levels will mean high combustion chamber temperatures.

Your description sounds like a tuning issue rather than metal to metal to me.....*EB

is the noise there all the time? hot or cold?

If you are worried about it being the timing chain you can pop the valve cover off and look down the front timing cover to see if the guides are broke or look for railroad tracks on the inside of the front cover. Also I have seen people with the wrong valve cover so you can look at the inside of that while you are in there and see it the rocker arms are hitting it.