Cold Idle Problem

[littlemisstubby]

Did the ecu temp sensor throw an error 22 code when you unplugged it?

[temo_shay]

How would i know if it threw an error code?

[littlemisstubby]

The engine management light will show on the dash.

Check for error codes using this guide -
http://www.mr2oc.co.uk/know-your-2-know ... bartid=162

Instead of the SST use a paperclip. If the ecu temp sensor threw an error the em light will flash a code 22.

[temo_shay]

Ok thanks ill try it and update with what happens

[temo_shay]

UPDATE.. Reset ecu by unplugging efi fuse, let car warm up and checked fault codes, got number 22 and 24 showing up which is coolant temp sensor and air intake sensor. Where do i go from here? Can they be cleaned or anything? Or have i got to source new ones? Thanks in advance.

[littlemisstubby]

The error 24 is the airbox intake air temp sensor I referred to. If you swap it with the sensor on the engine bay lid it should help things, if the original is still attached of course.

The error 22 may be just down to the sensor being disconnected with the engine running.

Id swap the airbox sensor then reset the ecu by pulling the efi fuse for 5 minutes. Then take the car for a run and see if the error 22 (or 24) returns.

If it does then you need a new ecu temp sensor. They are about £15 from Camskill.co.uk.

[temo_shay]

Thanks alot, ive swapped the airbox sensor with the engine bay lid sensor and it idles quite abit nicer, havent checked if the fault code has gone yet tho. And fault code 22 come up when the sensor was plugged in? Does this mean i need a new ecu temp sensor? Thanks again in advance, much appreciated.

[littlemisstubby]

Try an ecu reset, then give the car a good run out. If the code 22 is still there then you may need a new sensor. Is the wiring in the ecu temp sensor connector ok? Sometimes the wires can corrode and become weak and snap off.

[temo_shay]

The codes have all gone now, but my cold idle is still 900 same as my warm idle so ive just ordered a new ecu temp sensor, for the sake of £13.99 thought might aswell lol thanks for the help!

[temo_shay]

Ok changed the ecu temp sensor and guess what? No change. Im thinking about just giving up as the car idleing at 900 when cold and when warm doesn't actually affect how it drives or how it runs.

[littlemisstubby]

Does your car have the cold start injector time switch? Check for a grey plugged sensor next to the green ecu temp sensor.

[temo_shay]

yes there is a grey plug right near the ecu temp sensor mate, is there anything i can do to test this though as i don't want to keep buying things that might not make a difference lol

[littlemisstubby]

yes there is a grey plug right near the ecu temp sensor mate, is there anything i can do to test this though as i don't want to keep buying things that might not make a difference lol

I'd test the sensor in a pan of hot water. You may need a thermometer though.
Using a multimeter check the resistances of the sensor against this guide -



The n/a resistances will be roughly the same as the turbo ones in that guide. If they are wildly out or you can't get a reading at all then the sensor may be duff. Check its wiring connector too and see if the terminals are clean and the connector pushes on ok.

If it is fubar then I would look for a good tested used one as new sensors are about £200 iirc.

[temo_shay]

UPDATE; ive also replace the cold start timer injector switch thing lol gave the car a service, yet the idle problem remains! And when the engine is cold, when revved it goes to die. But it is fine when its warm?