No fuel additive or "better gas" is going to make your problem go away.
I suspect you have a vacuum leak somewhere in your system. What is
happening is that when the car is cold, whatever line or gasket running to
the intake manifold or sealing it, respectively, is worn out. As the car
heats
up the hose or gasket expands sealing the leak.
If you hook a pressure gauge to one of the vacuum lines you can verify
it is a indeed a vacuum leak very easily.
You will see your gauge wonder up and down as
your car moves from 1400-2000 RPMs.
If this is the case then do the following.
To solve the problem, first inspect, and replace if necessary, all hoses
leading to the intake manifold. Replace the PCV valve (cheap $2.49
at any autoparts store).
Provided all the hoses are good and you still have the problem, get a
new intake gasket from NAPA (just bought one the other day for $16)
and replace it. If that still doesn't solve the problem, then you will have
to separate the throttle body from the manifold and replace the gasket
(about $5) that seals the manifold the throttle body.
Again I doubt you will have to do all this things, but if you do as you
can see, if you do all the work yourself it is very cheap (under $50).
Now, if this still doesn't solve your problem:
pull out the injectors and replace the O-rings around then. Since they
are plugged directly to the manifold they could be causing a vacuum
leak.

I hope the advice helps, keep us posted. So many people receive advice
and never bother to post the solution to their problem once they
actually fix it. Thank you to those who do.

- JR
"Delpie" <delpie@aol.com> wrote in message
news:20031202232744.11003.00000074@mb-m24.aol.com...
> How harmful are the additives that are sold to clean fuel injecters and
the
> like..
>
> I have a 1994 Integra with 209,000 miles and it still purrs and runs
great.
> For about a year I have a cold weather reving problem that lasts for
about 1-2
> minutes upon startup and when it has been sitting for a couple of hours.
It
> revs from 1400 RPM to 2000RPM rapidly until it warms up and then settles
down
> to a "normal" idle...about 800RPM.
> My mechanic said to try a few tanks of premium gas( I have always used
regular)
> and I am on my second tank and upon startup it is getting better, but
after
> sitting for a couple hours I still get the reving problem!....In case this
does
> not work I was considering a "cleaning additive " of some type.
>
> Any thoughts???