Check engine light
 

For the past several weeks I've been having a problem with the check engine
light on my 1999 Miata, 79,000 miles. The first time it happened was when
starting after being parked for about two hours. The engine ran very rough,
almost stalling, with the check engine light flashing. I checked the gas cap
and fuses but saw nothing wrong. After driving about a mile, the engine
suddenly started running normally, and the light went to solid. The next day
I went to the dealer, who checked the code and said I need new wires and
plugs. I had them do that, but the next day I had the same problem. This
time the dealer said it was the catalytic converter, which was still under
warranty. They changed that, but the problem recurred. The light then went
out by itself after I had parked the car for two days without driving. Since
then it's happened twice again. The dealer checked and said it showed the
same two codes (random misfire and cat converter). After checking with Mazda,
they now think it's the ignition coil pack, which is on order. Right now the
car runs OK (though there seems to be an exhaust rattling which I at first
thought might be the cat heat shield) and the check engine light is on solid.

A possible contributing factor is that back in October the car got partially
flooded - parked in an area that turned into a giant puddle, and ended up with
about an inch of water in the foot wells. It ran fine, though, and a
different dealer told me at the time that the water shouldn't cause any
problems (main concern was getting the carpet dried out properly) since all
the electronics are up high.

Any ideas about this?

Barry

Check engine light
 

"Barry" > wrote
> After checking with Mazda,
> they now think it's the ignition coil pack, which is on order.

The '99 coil packs are known problems . I think it's likely your dealer has
identified it properly. Let us know how it works out.
--
Ken Lyons '97 Brilliant Black/'90 Classic Red
Inside the Beltway
[Remove the first two digits to reply]

Check engine light
 

> A possible contributing factor is that back in October the car got
partially
> flooded

I had symptoms similar to yours after buying my 95 this winter - the dealer
had washed the engine and there was water in the spark plug wells. Pull your
plugs, dry it out, and then let the car sit a bit with a warm engine and the
plug wires pulled to allow any moisture to evaporate.

My check engine light came on with the problem, but I don't know what codes
were involved. What's more, after three months, it went back out by itself -
I didn't have to pull fuses, etc.

Check engine light
 

> Pull your plugs, dry it out, and then let the car sit a bit with a warm
engine and the
> plug wires pulled to allow any moisture to evaporate.

Sorry, meant to say "pull your plug wires", not the plugs themselves. You
just need to get the moisture out from being trapped in the plug wells.

miker

Check engine light
 

>> After checking with Mazda,
>> they now think it's the ignition coil pack, which is on order.
>
> The '99 coil packs are known problems . I think it's likely your dealer has
> identified it properly. Let us know how it works out.

It looks like the problem is finally resolved, and it was the coil pack.
However, it took a while for this to become clear. A few hours after the
dealer replaced the coil pack, the check engine light came back on, but
without the roughness that I had experienced earlier. It turned out that the
catalytic converter had to be replaced again, because the ignition problems
with the bad coil pack ruined the cat (for the second time).

Check engine light
 

"Barry" > wrote
> It looks like the problem is finally resolved, and it was the coil pack.

Thanks for the follow up, Barry. It's always nice to know how thing turn out
(and get affirmation of my wild-ass opinions). Glad it worked out for you.
Sounds like you have a decent dealer there.
--
Ken Lyons '97 Brilliant Black/'90 Classic Red
Inside the Beltway
[Remove the first two digits to reply]