missing

I bought my 97 M model at 36K miles, and have driven it for 4 years. Now
has 88K. On a recent highway trip it started missing when ever I
accelerated, but would smooth out when I let back off the gas. This has
been a gradual onset, but seems to be getting worse. If I start off very
easy with just a slight amount of throttle, it's okay, but any excess
throttle and it drops down to three cylinders. Is this a spark plug thing?
Any ideas? Thanks.

In article >,
"Baby Grand" > wrote:

> If I start off very
> easy with just a slight amount of throttle, it's okay, but any excess
> throttle and it drops down to three cylinders. Is this a spark plug thing?

Sort of. Start by replacing the plug wires. That may be all you need.

--
Lanny Chambers, St. Louis, USA
'94C
the alignment page:
http://www.hummingbirds.net/alignment.html

Baby Grand wrote:
> I bought my 97 M model at 36K miles, and have driven it for 4 years. Now
> has 88K. On a recent highway trip it started missing when ever I
> accelerated, but would smooth out when I let back off the gas. This has
> been a gradual onset, but seems to be getting worse. If I start off very
> easy with just a slight amount of throttle, it's okay, but any excess
> throttle and it drops down to three cylinders. Is this a spark plug thing?
> Any ideas? Thanks.
>
>
How old are your plugs and plug wires? Almost always the cause of what
you are descibing and it will throw a code because of the unburned
hydrocarbons being sent down the exhaust from a misfire. The Miata
needs new plugs and wires about every 36K miles, IMHO.

Tom
92 Red