X20xev poor idle=stress

[J18BEY]

Pulling my hair out with this one, fault seems to keep changing so hope you guys can help cause I'm at my wits end. I'll start from the beginning to give you an idea of what's going on.

I recently changed my radiator and fitted a cool running thermostat at which time I disturbed my crank snr which was on its last legs. After this I got the usual crank snr symptoms, eml flashing poor running and idle. I then used the car for two weeks like this as it was bearable.

I then ordered a new crank snr and fitted it but I'd been sent the wrong one (red top one) and the car would not start but made a few pops and bangs. So while I was waiting on my right snr I fitted the old one at which point the eml was constantly on and ran in limp mode so I defo know this was the original fault.

Once it arrived I Fitted the correct crank snr and car was running great no eml, pulling well but slightly high idle 1100-1200rpm I then disconnected the battery to clear out any codes that may be left in the ecu.

I reconnected the battery and took the car a spin straight away, once again it ran great pulled well but now at idle the eml comes on and it struggles to idle and cuts out, if I start driving again the light goes out within 10sec and it drives great until you come to a stop again and it idles then the light comes on again and it idles poorly.

I'm going to try cleaning out the ICV but not confident this will have much effect on it. Any ideas you have would be great as I'm unsure which way to go next with it? And if someone could explain the paper clip test to me I'll get the codes out it and stick them up. Cheers in advance.

[J18BEY]

Cool running thermostat is going to be swapped for the original today. I'm thinking maybe that car is running too cool ( it doesn't leave the blue on the gauge at all) and maybe is fooling the car into running on auto choke and over fuelling. Started the car from cold this morning and ran ok then after few mins symptoms started to appear, took it a drive and held up the revs till it got to 90 degrees and it idled ok with no eml. Took it another drive and and temp returned to the blue, stopped again and guess what poor idle and eml. Hopefully I'm heading in the right direction?

[5853moore]

Be the ICV mate get a new one and go from there! my x20xev doesnt idle great if im honest with you!

[sribobby]

Yip definitely worth cleaning icv out, it doesn't cost anything! At least you could rule it out if nothing else.

[Ricky180b]

Temp sensor switch

[colin1]

...if someone could explain the paper clip test to me I'll get the codes out it and stick them up. ..

Unplug the diagnostic plug and short across Pin A and Pin B
Yours is the ecotec but for anyone else not familiar

a. for ecotec, turn ignition to ON
b. for anything not an ecotec, start car engine running

Sit in the driver's seat and wait for the EM light to flash '1 2' three times - that's one flash (1) followed by two flashes (2)
Next will come your actual fault code(s) that's codes in plural because you need to be mindful of the fact that you may have more than one. Fault codes are broken down in exactly the same way as the '1 2' opener/closer
Finally, once it's spooled off everything that's wrong with your car, it will run through the '1 2' sequence again.

So it should look like:

12 12 12
17 29 31*
12 12 12

at which point it will start to repeat the sequence until you turn the engine off

*three random codes that I plucked out of thin air

[colin1]

On top of that
what everyone else in the thread said about cleaning the ICV.
Clean the throttle body as well, using lollipop sticks, a small wire brush and a can of carb cleaner used sparingly.
Don't be tempted to use a screwdriver to scrape it or you'll run the risk of keying the sides of the throttle body and make it even easier for soot and carbon deposits to grow back.
Check that the gasket for the box that sits on top of the throttle body hasn't gone a bit flat and lifeless, the simple act of buying a new one (for pence) can sometimes sort an annoying problem.

Check all of your vacuum unions around the engine bay (and the ecotec has a few) sometimes given away by a faint hissing. If they're perished, replace them. This will certainly smooth out any idle irregularities.