Engine: 2.0 Carb B200K/B200F: Idle Valve

[Angie]

I think I might have asked about this before but I'm too lazy to search! I've been trawling Ebay to see what's available and it's very confusing, as the prices vary from around £30 to nearly £200. Anyway, I wondered about this one, item 350586480732, which is one of the cheaper ones and apparently fits a 2ltr engine, 1992. Has anyone bought one, and if so was it satisfactory? What's the catch?! The mechanic said I should go for a cheaper one and see if there's any improvement. He's cleaned the old one but says that after nearly 190,000 miles there's likely to be wear in the moving parts so replacement is advised.

[Clifford Pope]

Yes, they do wear, and yours will be worn at that sort of mileage.
They don't wear out - it will still work after cleaning, but it develops a loose spot corresponding to the normal idling position, so you don't get a stable idle. Also it becomes sluggish in responding precisely to sudden closing of the throttle, so may stall if you slow and declutch quickly. Alternatively if you ease of gently it may stick at a high idle, and then perhaps slip back to normal after a while waiting.

I've used the cheap ones and can't see any difference.
They do need cleaning regularly as part of the breather and flame trap maintenance regime.

[Angie]

Thank you, Clifford, all of those symptoms are present fro time to time. I'll go for the cheaper part then, can't see the point of lobbing out mega-bucks if not necessary!

[Angie]

Shiny new idle valve fitted, now the idle is staying at 1,500rpm! The code is 1-2-1 so I might as well get a MAF meter but is there anything else I should consider. It seems to me that if the MAF is faulty it must affect a lot of other things, but does that include idling? Most of the symptoms mentioned by Clifford are still there. Incidentally the idle speed immediately after starting is about right but much worse at running temperature.