Is it my knock Sensor? '90 90Q 20V

[Huw Powell]

> Well I have replaced the O2 Sensor, changed the oil Castrol Syntech
> (5w50)& Filter (Mahle), replaced the Air filter (K&N), replaced the Dist
> Rotor and Cap.. I still have the lag at 4000 RPM but kicks back in a
> 4500 rpm...  I also have a slight rough idle after the engine is warm. I
> also am noticing a weird noise (Like paper being torn) at 2900 rpm...
> only lasting a moment.
>
> Ok so are the knock sensors easy to get to?  How much are they?  Would
> they help me pass my emmisions if I were to get new ones?

The knock sensors should not affect emissions.  What they do is retard
the timing (causing a sense of loss of power) if the slightest hint of
preignition is detected.

To see if that lag is related to this you could disconnect them and see
if you get knocking instead of the lag at that point.  But get your foot
of the gas if you do, knocking is not a good thing...!

My 89 90Q (10v) used to get balky in hard acceleration after 30 min heat
soaking on hot days - until one day I got this "coffee can full of
bolts" sound instead... apparently my knock sensor had gone south.

On the 10v, which only has one, it is mounted on the port side of the
block, by a single bolt, with an 18" or so black covered cable ending in
a typical 2 pin AMP connector held by a little bracket near the battery
box.  Maybe the 20v ones are similar, if you hunt around.

And good luck with that inspection!

--
Huw Powell

http://www.humanspeakers.com/

http://www.humanthoughts.org/