Revs up and down every 2 sec

[CMF_spikem]

Hi All, K11 2001.

Just replaced cam chains and tensioners now when the engine starts it seems ok then goes into a recurring cycle of revving up and down continously. Odd times it will settle down to a high rev idle or continue revving for a short while after taking the accel off.

I have read the other posts on resoldering the Tb,valve cleaning and checked for vacuum leaks but just wondered before I start on them if there is something obvious i could have missed re assembling the engine as it was running fine ( albeit noisy) before I stripped it down. . Engine timing is fine by the way and runs smooth No engine management light on

 

[CMF_syko]

might just be as simple as taking the car for a good thrash buddy

 

[CMF_DECIM8]

You've adjusted the throttle position sensor. I know as when I crashed my R34 and stipped it I did this and just left it be cause it was being wrecked.

It will prob be next to the throttle body somewhere, never actually noticed where it is on the micra.

You may also need to disconnect the battery for a minute and pump the brake. This will reset the ECU. This will allow the ecu to relearn the idle.

 

[CMF_danno88]

you can reset it by doing an idle air volume learn using consult 2, which you prob wont have lying around.

 

[CMF_spikem]

Now sorted out. Thanks for the advice. Turnrd out to be the idle control valve. Not too sure of its operation but noticed the notch on it wasnt fully up to the v shaped cut out so gave it a twist as it was quite sriff and got it back to what looked like its original position. Also gave it a quick burst of carb cleaner. I would imagine this rotates itself when operating ,but once the car started all was back to normal.