Engine noises...problems??

[Jason Puckett]

I've already checked the archives but can't figure out
the proper search term to find the info I want.
Everything comes up with so many matches I can't sift
through them all.

My '93 SE-R is making noises (detonation I think)
under load.  Even mild acceleration in 5th gear does
it.  It sounds like there is a pebble in one of the
cylinders.  Cruising on the freeway at 65 its fine,
give it a little gas and you hear it.  It just keeps
going as long as you're on the gas.  At first I
thought it was because I live in Hell...I mean Phoenix
(its hot as hell) but it was doing it tonight at 10 pm
when its only about 90 degrees out.
Engine temp never moves.  I have the NISMO radiator
and 1.2 bar radiator cap.  Fresh coolant/water.
In the last 6 months I've done new water pump, plugs,
wires, cap, rotor, injectors.  Has about 94K on
engine.
JWT POP intake, timing bumped to 17.

Should I take the timing down to 15 first and see if
that helps?  Shouldn't the knock sensor retard it
anyway?

Is it time to get a Spec V??  :)

thanks for any help,
Jason