Idle Speed Valve Gasket? Remove without removing air intake?

[andymaxwell]

Hi All, quick question if that's ok.
I would like to remove my idle speed valve from my 1998 1.8 RS Import. Do I need to purchase a gasket for it, and can I remove it without taking off the throttle body?

Many thanks :)

[Mazda Mender]

Why are you removing it?
M-m

[Lazza]

I doubt you'll get the ICV off without removing the TB. It's held on with 2 big Phillips screws which often need an impact driver to undo them.
I've never had to replace the gasket myself... but if I didn't have a spare lying around, sods law says I would tear it.

[andymaxwell]

Thanks for the replies. I'm investigating a minor high idle speed problem. I've looked through many forum posts and cleaning out the ISV seems to be a good place to begin.

I don't wish to lumber you with the problem as it has been done to death in other places, but just in case I'm on the wrong tack and you fancy a look:
* Car sits at 1050rpm when warm, even after setting the base idle (jumpering the diagnostics box) to 850rpm.
* If I drive up to the traffic lights *in* gear the revs will drop below 1050 and carry on until it stalls. But if I instead keep it rolling, depress the clutch and stop the revs will climb back to 1050rpm.
*When the engine is cold and I'm coming to a stop, occasionally the revs will drop down below 1050rpm but it is accompanied by a hunting sound (feels like it's going to stall too). The car will then 'notice' this and the revs then climb back up to whatever they were before (being cold usually above 1050rpm).

For your further info I have already:
*checked the PCV valve (it was all ok but replaced the rubber socket thingy in the cam cover anyway)
*checked all breather hoses those leading to the throttle body from the cam cover
*cleaned the throttle body (the grey 'seal' on the bfly valve was already missing)
*changed spark plugs
*changed air filter
*cleaned air flow sensor in the air intake

To do: Check charcoal filter and hoses.

[Lazza]

A few things I'd check - engine temp sensor on the back of the head, O2 sensor & MAF but first I'd check to see if the neutral switch on the gearbox and clutch switch on the pedal are working.

[Mazda Mender]

but first I'd check to see if the neutral switch on the gearbox and clutch switch on the pedal are working.

M-m

[andymaxwell]

Thanks chaps I will give it a go and report back :).

[andymaxwell]

When checking the sensors and switches I think I'm going to get a garage to do it, I have a multimeter but am fairly clueless about what settings to use and more importantly I guess what voltages to look for (unless there are posts I've missed on how to check these things?).
I guess with the switches they are either on or off but would a garage know all the correct voltages to look for when checking the sensors?

[Mazda Mender]

Where are you?
M-m

[andymaxwell]

In the good old south-west, Bristol. And you?

[Lazza]

In the good old south-west, Bristol. And you?

In his profile info. That's a nudge by the way. Location helps us recommend someone close to you who might be able to help