Miata Mailing List: March 1993, Message #31
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   From: (none)
Subject: Re: two problems
   Date: (none)

On 10 Mar, 13:26, Alan Dahl wrote:
> Subject: two problems
> 
> Car: 1990 model (built May 1989), 63,000 miles
> 
> Problem #1:
> 
> When I come up to a stoplight and let off the gas and push the clutch in the  
> RPMs drop to about 300-400 and then speed back up to about 850. Sometimes it  
> studders and almost (but never quite) dies. It doesn't always do this, just  
> sometimes. Also when it's cold idle RPM is about 1250 or so. Idle is 850 at all  
> other times.
> 
>-- End of excerpt from Alan Dahl

I don't know about problem #2, but this one is mentioned in Miata
Magazine's tips section.  I've experienced a mild case of this myself,
too: a bit of a stumble when approaching stop signs.  The magazine 
recommends increasing the idle speed and explains where the screw is 
to do this, and how much (little!) to turn.  My symptoms went away 
after a normal service by my dealer - no surprise since they have all 
that fancy electronic equipment.  Adjusting the idle speed should be 
a regular part of the tune-up.  I'd expect the idle RPM to be higher 
in the cold - that's just the automatic choke working correctly.

OTOH, I think the recommended idle speed is 750-850 RPM.  Maybe there
is some other aspect of a service (even just fresh oil?) that might
clean up running enough that increasing the idle is not required?
Anyone care to contradict me on the above???  ;^)

-- 
-- Paul Jasper
-- RATIONAL
-- Object-Oriented Products
--