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[Andy H]

There do seem to be a lot of vacuum connections below the throttle body. Any one of those could let in enough air to cause a fast idle.

[alexw80]

Won't comment on the idling as I don't know, but as a reference (mine is v reg 2.0 CDX / X20XEV engine), when I did the paperclip test I got exactly the same as you, i.e. light went out shortly after putting ignition on then just stayed out.

I have had it on a tech2 since then and have been told there are no error codes showing.

Sounds like there's nothing stored on mine then. Thanks for the info

[alexw80]

I suppose you have already read these guides

How To Clean Your 2.0L IACV and Breather Jet

Cleaning the throttle valve assembly Omega 2.0 16V

Cleaning X20XEV Idle Control Valve

Yes, they helped a lot. Don't think I'd have tried it without those guides. Although, still not done the large hose at the back on passenger side of engine yet.

I'll have another once over tomorrow to see if I can see/hear any air leaks in the pipes. Don't suppose anyone has any ideas as to the most likely place it could be?

[Shelby]

If you have some carb cleaner, I would try spraying that around the vacuum pipes etc.  If you have air being sucked in, it will draw in the carb cleaner and you will hear a noticable change in the engine.

What ever pipe etc. you were spraying is the area for the leak.

[alexw80]

Had a good look and feel round today, can't find an air leak. So thought I'd check the connectors. Took MAF connection off while the engine was running and it dropped to a low rev but very rough, almost to the point of it cutting out. So assuming the MAF is working fine. Went onto the IACV connection, engine was hunting between 1k-2k, took the connector off and the car hit just under 2k and stayed there, no hunting. Re-attached it and she started hunting again. Sticky IACV?

[Andy H]

I would expect a sticky idle control valve to alternate between too fast idle and too slow idle (maybe even stalling).

It might be worth another look at the cleaning of the valve though because it appears to use a 'balanced port' design. Two valves on the same actuator shaft, one gets pulled open by the manifold vacuum, the other gets pulled closed. If the hidden passage in the valve body is blocked it might be causing the manifold vacuum to pull the valve open  :-/

[Abiton]

Not sure what this implies for you, but I just tried disconnecting the (electric connector of the) IACV on ours while running and it cuts out very shortly afterwards. I couldn't be bothered to let the engine warm up fully from cold, but I'd expect the same TBH.

This makes sense to me, throttle closed, and no power to open the IACV so it too is closed; no air into engine >> stop.

I guess this does suggest that your IACV isn't closing correctly. 

I picked up an ebay one for £30-odd when ours was on the blink, and 3+ years later it's still going strong.  Worth a punt I think, if another clean doesn't help.

[alexw80]

Well, stripped it off again and gave it a thorough soaking this time. Put it all back together again, and nothing has changed.

Stumped. Got a mate who's a mech, will see if I can get hold of another IACV to try it and see if that works. If not, a trip to my local garage may be in order. Unless anyone can sujest anything else?

Oh for the days when I could get by with just using a push bike lol

[Andy H]

If you can get it on a code reader that shows live readings you should be able to see if the ECU is trying to close the IACV or if it is holding it open for some reason.

If it is trying to close it then you are back to checking for air leak or faulty IACV.

If it is holding it open then check the sensors for duff readings.

[TheBoy]

symptoms suggest air/vac leak.

96 on, 2.0l use 4 digit code, so no 1-2 start of sequence.

[alexw80]

symptoms suggest air/vac leak.

96 on, 2.0l use 4 digit code, so no 1-2 start of sequence.

Cheers for that, didn't know which code sequence mine used.

Fingers crossed I've got a mate of mine sorting out another IACV for me to try. If it works I'll get one. If not, searching for leaks again.

[alexw80]

Replaced the IACV with one from the local friendly breakers. £10, works like a dream. Just a slight blip from time to time on tick over, possibly needs plugs changed as I think the rocker cover gasket has gone. Idles just under 1k, no hunting what so ever. 

Now just need to clean out the pipe at the back end of the engine, passenger side. I'll do that when I do the rocker gasket.
What's the best way clean the pipe? Take it off and drown it in carb cleaner or better to use something else?

Thanks for the help guys. Much appreciated.