stalling NA

[tjcool]

hey guys
I have the 90 NA and it is playing up
when i pull up at lights down through the gears and put the clutch in at the lights the car stalls

i think it is the little cylinder ( cant remember what its called ) slave cylinder ? that is on the throttle body to stop the throttle snapping back not doing its job
has anyone had this prob ?
i adjusted the screw to make it come on earlier but that has only temporarily fixed it
im sure that this is what the problem is and they are 125 bucks new
any advice?

[Juffa]

Sounds like a known problem, idle droop. Usually fixed by adjusting the idle screw. Try a serach on this forum or the USA big forum, you should find a stack of hits.

Here is one ==>> http://www.miata.net/garage/ignition.html#idle

J

[tjcool]

thanks but no its not the idle
the car runs fine
starts fine , never stalls

only when cruising along and the lights change i slow down through the gears get
into second , push the clutch in - car splutters and if i dont heel toe it to grab the revs it conks out

normally idles perfectly at 750 rpm
it is like that little cylinder just is not doing its job
like it is not returning the car to an idle slowly it is just snapping back on the idle spring and therfore cutting the supply of petrol

[Garry]

I'm with Juffa. Sounds like classic \"idle droop\" to me. You need to adjust the base idle speed

[kitkat]

im woth the others... idle droop. Happened to our NA6... its symptons were exactly as you described them.

In our case the fix was when i put in a 4.4mhz crystal in to lift the rev limiter up and a side effect is that it idles slighly higher, it all worked out perfect

As Gary said, adjust your base idle.

[Lucky_Luke]

Hey tj, mine used to do that too, and i thought it would be fixed by adjusting the idle screw but never worked, after a long time i finally figured out that it was my idle speed control unit, the valve under the throttle body, mine was stuff so i bought 2nd hand one( as new theyre like $530) and wallah! all good.
to check if yours is bust... pull the plug off it and measure the resistance between the terminals ( when cold) if its between 1-13ohms its all good.. if it goes to infinity or some huge Mohm valve its stuffed..
Well thats what was wrong with mine .. prob worth checking anyway.. possibly check that the other air valve on the top of inlet manifold is operating properly too.. this one is a 'dumb' valve operating only on coolant temp... but it too could be causing trouble..

L.