[Supras] Two knock sensors or one?

[Michael Bringle]

Don't forget the O2 Sensor and ignition timing.  I'm running the original
one at 154k miles and just passed smog with flying colours today :).  The
car is also slow and goo now because all the original eq is back in.  There
was a post a while back of a graph.  You looked up your numbers on the graph
and it listed areas to check.  Wish I could find that now.  But how hot was
your car?  Did they test it right away or let it sit?  Here is a good
comparison of tests done on my car yesterday and today with the same setup.
The only difference is that yesterday they "tech" let the car cool down for
over 30 minutes before he started it and tested it right away:

15 MPH
Test Yest  Today
RPM  1542  1585
CO%  14.9  15.0
O2%  0.0    0.0
HC   106    54
CO   0.11   0.03
NO   79     11

So drive around for 20 minutes and drive it right onto the dyno :).  Cut my
HC in half!

-Mike
89T BST++
http://www.CygnusX1.net/supra


-----Original Message-----
From: supras-bounces at supras.com [mailto:supras-bounces at supras.com] On Behalf
Of Hacker J
Sent: Monday, July 09, 2007 9:18 AM
To: supras at supras.com
Subject: Re: [Supras] Two knock sensors or one?


One knock sensor for the 7MGE.  The turbo has two.

Are the HC numbers really high, or just a little bit?   The little bit over
cases can be a real pain to diagnose.  Start with timing, fresh plugs and
anything dubious in the ignition system. It's usually misfire or ignition
related. Valve timing, deposits,
faulty EVAP, stuff like that. Anything that send unburned fuel out the
exhaust. 

Unless there is a lean misfire looking at the feedback loop is
usually useless when dealing with HC.


Jon
90T


----- Original Message ----



Hi to all,

We're trying to get my son's 1990 Supra to pass state emissions. It has a
code 52 for knock and (I am assuming) high HC levels due to spark retard.
This is a non-turbo car. There is some debate as to whether there is a
second knock sensor behind the starter. I can't even see a wire going that
way, never mind a sensor. I really don't want to take the starter off, only
to find there is none! Any suggestions? Thanks for your help!

Bill

Perhaps refer to service manual at:

http://www.cygnusx1.net/supra/library/TSRM/







       
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