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MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Mon Feb 15, 2010 8:39 pm
by JDM-MX5
hey guys , i bought a NA6 and on idle it seems abit shakey .. like it goes fine then shakey shakey then fine , shakey shakey .. motor still runs strong tho, could it be the timing belt ?

is it cause engine mounts are old or signs of crank nose problem ?

any help would be appreciated.

cheers

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Mon Feb 15, 2010 9:01 pm
by Uncle Arthur
This is kind of like phoning your doctor and telling him you have a spot - and asking what it could be :)

If the motor runs strong through the rev range it is unlikely to be the crank issue I'd say.

Engine mounts - a good starting point.

Best thing is to visit your doctor - I mean MX5 mechanic. :)

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Mon Feb 15, 2010 9:17 pm
by jerrah
What RPM is the idle speed at? If the idle speed is low it will be a bit rough.

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Mon Feb 15, 2010 10:11 pm
by JDM-MX5
idle seems to be kind of normal , around 900rpm? i think cant remember ..

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Tue Feb 16, 2010 8:46 pm
by JDM-MX5
can anyone else help ?

cheers

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Tue Feb 16, 2010 8:52 pm
by jerrah
I would suggest getting a mechanic to look at it. If you adjust up the idle to around 1000rpm does it keep doing it?

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Wed Feb 17, 2010 4:19 pm
by JDM-MX5
hey man , where abouts is the idle screw ? ill give it ago .. can someone explain where it is ?

cheers

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Wed Feb 17, 2010 4:35 pm
by bruce
Me, me, me!
Spark plug leads?

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Wed Feb 17, 2010 4:57 pm
by Mr Morlock
buy a Haynes manual- small investment for a reference source. When were the plugs last changed etc ?

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Wed Feb 17, 2010 10:32 pm
by JDM-MX5
car just had a service , with new iridium plugs , so what abts is the idle screw around i can just find it ?

MAZDA NA6 engine , shakey on idle is this normal ?

Posted: Thu Feb 18, 2010 8:18 am
by bensale
Its not the plugs that can be a issue, rather the plug leads...

It sounds to me like you have the classic idle droop problem where the manual idle speed is set too low.

The manual idle control is located on the top of the throttle body. You'll need to bridge the 10 and gnd terminals in the engine diagnostics box to put the car in manual idle speed mode rather than ECU controlled idle. You then adjust the manual idle via the screw and match it to the ECU idle by unplugging the briding wire in the diagonstics box. when the idle doesn't change irrespective of it being bridged or not you've got it right.

Make sure the car is warmed up properly when you do this otherwise you'll cause it to idle ever worse and possibly stall.