Erratic Idle

[Pete W]

Hi,bit long winded this,so appologies in advance. Have had very erratic tick over for a long time, about 3-4 years. It is a 2000 2.0 VVTI, 1AZFSE engine. Have had it scanned on numerous occasions, and only fault that ever came up was the usual 02 sensor fault. Have changed all 4 sensors, and have no fault codes at present. Changed spark plugs, air filter, etc, still no change. Basicilly it idles at about 1200 when cold, and at about 600 when warm, but droppes down to 400, then shoots up to about 1000, then drops again, and so on. It will also cut out sometimes when you are turning the steering on tick over.I thought of mass air flow meter, but can't find one anywhere. A friend suggested cleaning throttle body, which i have just had done. It now idles at about 1900 when cold, and 700 when warm. It seems more even when it is warm, but i think the cold idle is very high. Any thoughts would be gratefully accepted. Thanks very much.

[Jamesbelfast]

Have you checked the engine coolant temp sensor and the inlet system for leaks?:)

[Pete W]

Engine coolant temp sensor was checked by scanner, he put it on a graph, and it was working o.k. Not sure about air leak, will find out. It runs fine apart from tick over.