D16a6 CRX SI motor in my 4dr ef dx.


Bought a CRX with this motor in it, so when I swapped the motor in the CRX this old SI motor I put in my daily driver since it was a slow dx and burned oil.

Ran good for almost a whole year.
really strong motor, very fast for what it is.

About a month ago I was driving at night and I noticed some pinging when under full throttle and low revs.

Last night was the same thing, so today i got a timing light and set the timing, it actually was slightly retarded.

So I set the ign timing to stock 18 deg or whatever.

Then I went to test it out tonight again, and as you would expect, its the same if not worse.

What the problem is:

Second gear from a slow roll, floor the throttle, kinda like a dyno pull, from 1k-2k revs its ok and 2k-2500 I hear a ping, then 2600-5k+ it sounds fine.

Sounds like it goes away after 2500rpm~

So what could that be?
What could be causing a ping under full load but only at low rpms?
Even when the timing is bang on?

Suggestions please.

Could I have skipped a tooth on the belt and the timing appears to be ok but its really out by a full tooth?
The motor feels really strong, so that makes me think it could be advanced a tooth.

Tomorrow I'll pull off the belt cover and check the cam timing.