[s-cars] pinging in 2nd under WOT
calvinlc at earthlink.net
calvinlc at earthlink.net
Sat Apr 5 21:57:24 PDT 2008
The most puzzling part is that it doesn't happen in 3rd - 5th where the
loading should actually be higher. Does the boost build to the same level
in 2nd that it does in 3rd-5th? What RPM does it mostly happen at? If it
is lower RPM when the boost isn't up too high then maybe the timing under
less than full boost is too far advanced. Very puzzling....
--Calvin
-----Original Message-----
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com]On Behalf Of Tom Green
Sent: Saturday, April 05, 2008 3:06 PM
To: s-car-list; Eric Phillips
Subject: [s-cars] pinging in 2nd under WOT
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
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