Spark Plugs - pre ignition issue

[amalventano at sc.rr.com (Allyn)]

after the 2.0 swap (standard compression) on the rieger, i can hear some
onset to detonation during shifts (as i accelerate into the next gear). this
is with standard timing, and only happens on really hot days. the only
electrical part i changed during the swap was the knock sensor that came
with the 2.0 block. my guess is that all it takes is a bad knock sensor.
i'll know soon enough, once i dig up the old sensor and throw it back on.
Al

----- Original Message ----- 
From: "Benjamin Harder" <vwtype53@yahoo.com>
To: <scirocco-l@scirocco.org>
Sent: Wednesday, July 23, 2003 11:36 PM
Subject: Spark Plugs - pre ignition issue


> I've been having an issue lately with pre-ignition (pinging) on my mk1's
> 2.0 16v engine.  Engine is freshly rebuilt with approximately 11:1
compression,
> running CIS-E, stock ignition, always on 93 octane, etc.
>
> If I set the ignition timing to stock settings (6-8 degrees) the engine
> will ping (my knock sensor is obviously not functioning).  I will then
retard
> the timing to around 4-6 degrees and everything seems fine... just the
fact
> that I'm losing some performance.  :(
>
> So, I checked my spark plugs to see that I was running the stock 3
electrode
> Bosch plugs for the 2.0 16v, which have a heat rating of 6.
> Due to my higher compression, I sourced a different Bosch plug with heat
rating
> of 5 (colder plug).  Thinking that this would dissipate heat faster
> and help solve my pre ignition issue... nope.
> The new plugs don't seem to have helped.
>
> Anyone have experience in the high-compression world with this pinging
> issue.  Sure I could run octance booster or race gas, but I know that
> there must be a way to run 93 pump gas... right?  :/
>
> If I go to a colder plug (like a 4 rating), would this possibly help?
>
> TIA!
>
>
> =====
> Benjamin Harder
> 86 Scirocco 16v
> 80 Scirocco 16v
> 93 Passat GLX
>
> http://www.geocities.com/vwtype53/
>
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