Need help again :(
 

Hi i recently posted on here about my cars random revving and holding the revs and cutting out etc.

I scanned the car and it came up as a Throttle position sensor. So i replaced the sensor and also idel valve thing thats located on top of the throttle body housing.

The random revving on tick over has now gone and it doesnt stall and no fault codes have came up, Although its still ticking over too high and when driving along at 3k or 4 for example when i lift of the accelarator the revs stay where they are untill i put into a lower gear so its like holding the revs at 4k when in neutral. I have noticed when i accelarate theres sometimes a hissing noise, im just wondering if maybe i have an air leak??

Any help on diagnosing and fixing would be appreciated.

check all your vacumn pipes, shiney black ones that mostly run horizontaly when looking at engine from front, might be an idea to remove the engine cover first to make tracing the leak easier:)

might be worth trying to re-set the ECU ???
just take the battery off for 30mins

just reset the ECU and no joy its still the same, i wouldnt no where to start when checking for air leaks.

Check IACV mating faces of housing to throttle body, apply sealant (blue hylomar etc) if the original gasket is damaged, clean off all remaining traces. Ensure IACV is seating correctly in its housing (located positively in the opposing countersink).

The original gasket looks fine tbh, i feel like im going round in circles trying the same things over and over. only thing i havnt checked for is air leaks as i dont no how to

Can of aerosol/butane gas spray it around the manifold/ iacv/ tb and if the revs pick up then you'll have found your leak.

Thanks, ill try it tommorow, have to drive the bloody thing to work now

Alternatly... look at the throttle body springs etc and see if they are sticking, spray some WD40 in and around that area to degrease it and free it up. See if that helps with the issue :)

Have the vis motors been disturbed recently or the plenum?