Slight shake/low rpm only when coming to a stop

[dorifta]

hey all


got a weird kinda problem when i stop...


i have an nb8a 90k on the clock but everytime i push the clutch in to stop the rpm drops under 700k the engine shakes but doesn't stall... i replace my plugs every 5000kms, im thinking its time for new leads? if so what are some decent aftermarket items that are apprentice wage friendly?

i might clean out me air flow meter with some electrical contact cleaner and might do the same for other sensors...


thanks in advance!

[owm]

Sounds like a dashpot problem:
http://forum.miata.net/vb/showthread.php?t=361955&highlight=dashpot

[dorifta]

thanks for that!

i didnt bother adjusting my idle as its currently on ~850... when they say lubrication, will wd50 do or shall i apply some grease to the throttle dampening valve?

[Alex]

Seems to happen to quite a few NB8A's, some worse than others

http://forum.miata.net/vb/showthread.php?t=127446
http://forum.miata.net/vb/showthread.php?t=127451

[owm]

WD40 is a water dispersant. Don't think it has much lubrication properties.

I used leftover engine oil applied using a cotton bud.

[dorifta]

ok i will try the cotton bud trick.. also spotted in one of the threads alex linked:

"Okay here's the scoop. Went home yesterday, cut a short bit of wire for the jumper. The car was already good & warm from the 20 mile drive home, and idle was at 850 (on computer). I wouldn't do this procedure cold - warm up the car first.

Here's what I did:
1. Put the jumper in between GND and TEN. Idle went to 800.
2. Adjusted (with a screwdriver) what TurboLover describes as the Air Bypass screw.
- to INCREASE idle turn COUNTER-clockwise
- to DECREASE idle turn clockwise
3. Set off-computer idle to 950.
4. Removed the jumper, idle back on-computer to 850.

This A.M. the idle dip was present, but very very slight. Idle would drop to 800 or 750 coming to a stop. If I weren't watching the tach closely I wouldn't even notice. Usually during my morning commute the idle will dip to 550-600 for the first few stops. A definite improvement. I may try setting the off-computer idle to 1000 to see if that gives any improvement.

steve
"

ill have a sus of that too n see how we go... the problem isn't that bad yet, more annoying then a problem... its time anywho to replace my leads i think, any suggestions?


cheers!

[owm]

If your plug wires or leads have never been replaced before, then it will be good to do so

I use NGK blues as recommended on miata.net.

Yes, do follow the procedures you have written to ensure your idling is set properly. This is applicable for those running on stock ECU of course.

[93_Clubman]

Also worth resetting the ecu by disconnecting the battery & pumping the brake pedal a few times.