plugs & hp increases

[Gregory Chan]

> Date:          Wed, 18 Jun 1997 10:12:16 -0400
> From:          Barney Ward <bvward at idt.net>
> To:            diy_efi at coulomb.eng.ohio-state.edu
> Subject:       Re: plugs & hp increases
> Reply-to:      diy_efi at coulomb.eng.ohio-state.edu

> Gregory Chan wrote:
> > 
> > > >Jeffrey: Another explaination for the HP increases you saw by changing
> > > >plugs (and I've heard this attributed to Bosch Platinum plugs in '92
> > > >and later 3 series BMWs) is that with that plug you're getting some
> > > >detonation and the knock sensor is dialing back the spark advance.
> > > >I've used Bosch Platinum plugs in my VW Jetta, it really liked them,
> > > >but it sounds like some cars don't like them for whatever reasons.
> > > >
> > >
> > Japanese cars don't like Bosch plugs. I spent days figuring out an
> > erratic idle problem which disappeared when I reverted to NGK.
> > My buddy was also having the same problem with the same cure.
> > I heard they work beautifully in German cars though.
> > 
> > gchan at compserv.senecac.on.ca
> Please explain how the nationality of the car affects plug type. Do they
> use different materials in the cylinder heads? This seems like saying
> "my Pinto runs good on Amoco, but my Vega likes Shell." What's the
> correlation?
> Barney ,
                I had a problem with an erratic idle speed where the 
car would cut out at the lights. I spent quite a while on this 
problem and eventually bit the bullet and took it to a shop. The guy 
checked the plugs and quoted me the price of a new set of plugs and 
half an hours labour. I said OK and he replaced the plugs and the 
problem went away, the car's idle was rock steady. Of course I have a 
lot of aftermarket parts in this car. The guy then proceeded to tell 
me that through experience he had determined that those plugs don't 
work that well in these cars. My buddy with an Integra was having the 
same problem and after changing back to the original plugs his 
problem went away. Other than that they performed OK and no, I 
can't explain why that happens.

You can draw your own conclusions from this but when my buddy changed 
his plugs and his erratic idle went away that convinced me. BTW my 
car is a Corolla GTS.

gchan at compserv.senecac.on.ca