Have you done a free rev while you watch or log the noise? If you get it
free revving, then you're pretty sure it's not knock and you need to
hunt for a noise.
 

Bill Cardell 
TurboDog's Dad 
www.flyinmiata.com 
www.fmwestfield.com 
orders 1-800-FLY-MX5S 
Before you call our tech line (970.464.5600) please check out the FAQ
<http://www.flyinmiata.com/FAQ/>  section of our website 


 

________________________________

From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of M. Ybarra
Sent: Sunday, November 09, 2008 9:29 AM
To: Miata Power List
Subject: Re: Obiwan Knock sensor acting up, any ideas?


I thought of that too.  However, as I noted below, the knock value ramps
up as opposed to an instantaneous event which would be an indicator of
knock, don't cha think?  

        ----- Original Message ----- 
        From: Bill Cardell <mailto:[EMAIL PROTECTED]>  
        To: M. Ybarra <mailto:[EMAIL PROTECTED]>  ; Miata Power
List <mailto:[email protected]>  
        Sent: Saturday, November 08, 2008 9:34 PM
        Subject: RE: Obiwan Knock sensor acting up, any ideas?

        Keep in mind the car is most likely to really knock at torque
peak, right around 4500.
         

        Bill Cardell 
        TurboDog's Dad 
        www.flyinmiata.com 
        www.fmwestfield.com 
        orders 1-800-FLY-MX5S 
        Before you call our tech line (970.464.5600) please check out
the FAQ <http://www.flyinmiata.com/FAQ/>  section of our website 


         

________________________________

        From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of M. Ybarra
        Sent: Saturday, November 08, 2008 10:11 PM
        To: Miata Power List
        Subject: Re: Obiwan Knock sensor acting up, any ideas?
        
        
        Well, I rechecked all of the intake manifold fasteners, they
were tight.  Did a once over on all the fasteners near the knock sensor,
they were tight too.  I went and picked up the new knock sensor and
installed it.  Took the Miata out and left the Link pad where I could
view the knock values.  The values increase from 1 to around 19 right
around 4500 rpm but that's about it.  So, it's a bit better than before.
I ran the car, hard 1st through 3rd, then went to 4th, coasted until I
was at 2000 rpm and then floored it.  No knock, but the same ramp up @
around 4500 rpm.  So, I believe it was the sensor, however it still
ramps up some (it's still well below the knock limit).  Is this normal?
I didn't check it with the original knock sensor that I got w/ the FM
kit.

                ----- Original Message ----- 
                From: M. Ybarra <mailto:[EMAIL PROTECTED]>  
                To: Miata Power List <mailto:[email protected]>

                Sent: Friday, November 07, 2008 5:54 PM
                Subject: Re: Obiwan Knock sensor acting up, any ideas?

                The intake manifold brace was removed when the FM turbo
kit was installed due to the inclusion of the PWR Twincooler
radiator/oilcooler.  The oil hose routing necessitates the removal of
the intake manifold brace.  The starter bracket is secure.  I haven't
checked all of the lower intake manifold nuts, but the ones I could
readily reach were secure.  I don't have any vacuum leaks so this is a
little less likely, but I will check tomorrow.  Also I have stage 8
fasteners of the turbo, DP and exhaust manifold.  These are secure as
well.  
                 
                I just ordered a new sensor (they are Bosch units from a
91 Porsche 944 w/ the 3.0 liter motor, bosch part # 0-261-231-006)
locally and will go pic it up tomorrow afternoon.  Hopefully that's it.
                 
                Myron
                 
                ----- Original Message ----- 

                        From: Ray Ayala <mailto:[EMAIL PROTECTED]>  
                        To: M. Ybarra <mailto:[EMAIL PROTECTED]>  ;
Miata Power List <mailto:[email protected]>  
                        Sent: Friday, November 07, 2008 4:36 PM
                        Subject: Re: Obiwan Knock sensor acting up, any
ideas?

                        The noise source may very well be on the other
side of the motor.  Peaking in a fairly narrow rpm range certainly does
suggest something resonating.  I've seen four such things over the years
... the intake manifold brace (loose bolt at the top end), the intake
manifold itself (brace missing and one loose manifold bolt), the starter
(front brace missing so the entire started acted like a tuning fork),
and a loose downpipe flange bolt.

                                ----- Original Message ----- 
                                From: M. Ybarra
<mailto:[EMAIL PROTECTED]>  
                                To: Miata Power List
<mailto:[email protected]>  
                                Sent: Friday, November 07, 2008 11:45 AM
                                Subject: Obiwan Knock sensor acting up,
any ideas?

                                Early this week, I was accelerating in
2nd gear on an on ramp getting onto the freeway when right around 5000
rpm and I got a knock event, just 1.  I went to 3rd to about the same
rpm and got another.  The Link pulled a substantial amount of timing as
a result.  I assumed I got a bad batch of gas, so I kept out of boost
and when I got home I put in some of my race fuel (about 2 gallons) and
left the existing map alone as I have been running this ecu street
setting for about 3 years.  Ran the car again and the same thing
happened.  I got the car home again and went to the knock screen on the
Link pad and rev'ed the engine to about 5000 in blips.  Since there is
no load on the engine I figured that it's shouldn't register anything.
Unfortunately the knock #'s rose to 40 really quickly then back down to
1.
                                 
                                Well, I figured that I have something
loose near the sensor (which is what Keith @ FM suggested as well) so I
put the car up on my lift this morning and checked every bolt or nut I
could get my hands on; bell housing, motor mounts, starter bracket, oil
pan, ancillary brackets all the way up to the valve cover bolts.
Nothing is loose.  So I figured that maybe the Quaife with all of it's
racket could be causing it, so I pushed in the clutch to quiet the gear
set and rev'ed the motor to 4500 rpm, the numbers shot up to 38 really
quick then came back down to 1 when I released the throttle just like
the first time.  So, I'm at a loss.  Could the sensor be going out or am
I missing something else?


                                
________________________________


                                

        
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