Fast idle 1200rpm constantly

[ETERNITY]

I have checked afm, hoses, done a compression test and all is well.

My mechanic says he wreckons its ICV

also moving away from 1200 revs it hesitates

just had a major service, and am replacing plugs next week

Any advice guys

[ETERNITY]

its a 325i tech 2

[Grrrmachine]

I'd suggest either fuelling or TPS. Check the resistivity of the blue temp sensor at the ECU plug (do a search), and also operate the throttle butterfly manually and listen for a little "click" just as it comes off its rest. The click doesn't mean it's working the way it should, but a lack of click is a good sign that the TPS isn't telling the ECU that the car is at idle.

Of course, ICV could be sticking, but a good blast of carb cleaner is usually enough to sort that out. Whereas TPS and Blue Temp Sensor issues are common to this engine.

[ETERNITY]

thanks

have cleaned out ICV but when its tapped the revs drop down.?

[Grrrmachine]

If the blue temp sensor is wrong the car will be running rich. If that's the case, the ICV will still be working its guts out buzzing away, and a tap might upset it a bit for a while - percussive maintenance isn't really how these cars work.

Get the multimeter out.

[e30topless]

sounds like someone has adjusted the TB

[ETERNITY]

k cool some good suggestions
much appreciated

lets see what brians concludes

[Brianmoooore]

Not uncommon for an old ICV to develop a bit of a sticky spot, but this is only usually a problem if you're asking it to work at an opening where it hasn't spent most of it's life - such as asking it to control an engine converted to and running on LPG.
Has the throttle body stop been got at? Is the TPS in full working order and set up properly.

[ETERNITY]

the tb and tps are all good.

My mechanic is still saying i should have the ICV changed.

Would it be worth testing the blue temp sensor and also can someone put up a link how to check this.

thanks

[Brianmoooore]

the tb and tps are all good.

What checks have you made?

[ETERNITY]

I havn't personally but my mechanic has checked, and he told me the tps and Tb are all good.

I asked him if they were all good and referred to this thread, and he confirmed that they are.I just dont want to buy a ICV if this is not the problem.

[ETERNITY]

Run up to temperature, switch off, remove ECU plug and measure between pin 45 and ground with a multimeter, should be between 300-360 ohms.

See pic below for pin to use.

thanks willnz

Excuse my lack of knowledge, but what will this test prove and if its not between 300-360, then what?

[Brianmoooore]

This is to test the 'blue' temperature sensor and its wiring.

[ETERNITY]

ok i will report back once i have checked blue temp sensor