Stalling Issue

I have a 92 Miata with almost 90k miles. The engine stalls sometimes
when I engage the clutch and put the shifter into 1st gear. If I
leave the shifter in neutral then no problem. Sometimes the engine
doesn't stall but rpms drop very low but when I take the shifter out
of 1st gear then back to normal.

Any ideas?

wrote:
> I have a 92 Miata with almost 90k miles. The engine stalls sometimes
> when I engage the clutch and put the shifter into 1st gear. If I
> leave the shifter in neutral then no problem. Sometimes the engine
> doesn't stall but rpms drop very low but when I take the shifter out
> of 1st gear then back to normal.

Check the clutch switch (above the pedal) as they almost always fail
around this mileage; on a UK MX-5 owners' club tech day something like
80% were dead. You can normally fix them with the spring from a
ballpoint pen, or just buy a new switch. If the clutch switch doesn't
work the engine will cut the fuel supply just as it does on the over-run.

Also flush out the idle air valve with throttle body cleaner (no need to
remove it - just remove the rubber hose from the big air duct) and then,
when the smoke has cleared (take it for a good run) reset the base idle
speed to 850rpm. This is worth doing anyway, but will also eliminate
the possibility of a sticky valve.

In article >,
Zog The Undeniable > wrote:

> > I have a 92 Miata with almost 90k miles. The engine stalls sometimes
> > when I engage the clutch and put the shifter into 1st gear. If I
> > leave the shifter in neutral then no problem. Sometimes the engine
> > doesn't stall but rpms drop very low but when I take the shifter out
> > of 1st gear then back to normal.

If it's also getting hard to slip into gear, time to rebuild or replace
the clutch slave cylinder. It's leaking, and not allowing full
disengagement. This is probably the most common mechanical failure on an
NA...and the cheapest to fix.

> Check the clutch switch (above the pedal) as they almost always fail
> around this mileage; on a UK MX-5 owners' club tech day something like
> 80% were dead. You can normally fix them with the spring from a
> ballpoint pen, or just buy a new switch. If the clutch switch doesn't
> work the engine will cut the fuel supply just as it does on the over-run.

UK models must be different, then. On North American NAs, the clutch
switch is just a starter interlock.

Lanny Chambers wrote:

> UK models must be different, then. On North American NAs, the clutch
> switch is just a starter interlock.

We don't have a starter interlock over here. Fixing the clutch switch
is known to cure "idle droop" when coasting to a halt or changing gear
on ours.

"Lanny Chambers" > wrote in message
...
> In article >,
> Zog The Undeniable > wrote:
>
>> > I have a 92 Miata with almost 90k miles. The engine stalls sometimes
>> > when I engage the clutch and put the shifter into 1st gear. If I
>> > leave the shifter in neutral then no problem. Sometimes the engine
>> > doesn't stall but rpms drop very low but when I take the shifter out
>> > of 1st gear then back to normal.
>
> If it's also getting hard to slip into gear, time to rebuild or replace
> the clutch slave cylinder. It's leaking, and not allowing full
> disengagement. This is probably the most common mechanical failure on an
> NA...and the cheapest to fix.
>
>> Check the clutch switch (above the pedal) as they almost always fail
>> around this mileage; on a UK MX-5 owners' club tech day something like
>> 80% were dead. You can normally fix them with the spring from a
>> ballpoint pen, or just buy a new switch. If the clutch switch doesn't
>> work the engine will cut the fuel supply just as it does on the over-run.
>
> UK models must be different, then. On North American NAs, the clutch
> switch is just a starter interlock.

There is another clutch switch that is above the pedal on N American cars.

In article >,
"Chas Hurst" > wrote:

> There is another clutch switch that is above the pedal on N American cars.

Isn't that to disengage the cruise control?

"Lanny Chambers" > wrote in message
...
> In article >,
> "Chas Hurst" > wrote:
>
>> There is another clutch switch that is above the pedal on N American
>> cars.
>
> Isn't that to disengage the cruise control?
It's connected to both the CC computer and the PCM/ECU. I am unsure of it's
complete function.