Miata Mailing List: November 1998, Message #64

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Early last week I drained my battery, and got a jump start.

Ever since that day, I have been having an Idle hunt problem.

Most of the time that I bring the car up to 4,000 rpms, and then
get off the gas, the engine decelerates rapidly down to 200 rpms,
bounces up to 1,200 rpms, does this for about 2 to 3 times, then stops at
850 rpms and sits there rock solid.

Sometimes I will bring the rpms up to 4,000 and get off the gas, and
the idle will fall slowly to 850 rpms and sit there like a rock.

The engine has only stalled once, and that was when I was under the hood,
playing with the throttle trying to cause it to stall.  I would jerk the
throttle
repeatedly and if I do it enough I can stall the engine.  It sounds like the
engine
is running to lean when it does go down to 200 rpms.

I checked the error codes and did not have a single error.

I drove the car on a 12 hour round trip this weekend hoping it would clear
it self up, and I did not.  On the trip I was doing 90+mph most of the way
and still was getting over 30 mpg.

Any suggestions,
91 A package
57,500 miles -  no repairs except for a blown clutch (I drive it hard)
I did put in new spark plugs and  PCV Valve only a few weeks ago.  Ignition
wires
were changed at 25,000 miles.  Jackson Racing CAI was added this summer.

-------
John Byrns
jbyrns@hoflink.com