[s-cars] pinging in 2nd under WOT

[Tom Green]

It must be raining and cold outside.  This fault tree analysis is  
only going to the
first branch, i.e., record and clear diagnostic fault codes.  Where  
you go depends
on whether you have codes or not.

Although it has been asked what octane fuel you are running, if this  
ping has
existed since last summer to some extent, I would assume you have at  
least
tried other fuels to eliminate the possibility of poor quality  
gasoline.  But, you
haven't shared that with the list or any other remedial action you  
have taken, i.e.,
checked the plugs and connectors and injectors?

The ignition connectors and knock sensor plugs are on the firewall.   
Regardless
of codes or what actions you take, clean the connectors, even if it  
is just to remove
and replace the plugs to scrape the crud off the connections.  The  
ECU doesn't
know the difference between an open circuit at the sensor or the  
connector.

Use a good quality gasoline and use injector and valve cleaners if  
they are not
included in the fuel.  The carbon that coats valves will coat the  
waste-gate and
interfere with smooth operation as well.

Before I would accept totally that the engine pings only in 2nd and  
not 3rd-5th,
I would put a knock detector and recorder on the engine to verify  
that it is a
knock and if it is one cylinder or more, assuming no solution has  
been found
before.

Tom

> Date: Sat, 5 Apr 2008 09:12:01 -0700
> From: "Eric Phillips" <gcmschemist at gmail.com>
> Subject: [s-cars] Stop the comedy! Real issues to solve!
> To: s-car-list at audifans.com
> Message-ID:
> 	<718a440c0804050912p53aa7c01m6eb7a56ace829ff at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Gents:
>
> Gots a 95 UrS with MRC chip, stock everything else.
>
> Lately a problem cropped up with pinging in 2nd under WOT.  Last
> summer, the car would ping slightly and shortly in 2nd @ low RPM and
> WOT.
>
> Now, the car pings at all RPM in 2nd @ WOT.
>
> Not in 3rd-5th.  I don't do WOT in 1st, so no data there.
>
> I'd like to sart a stepwise diagnosis before I go out and start
> throwing new parts at it.  Thoughts?
>
> Eric