Idling problems

[washie]

Hay fellers, I have a CK2 lancer, approximately 2 years ago it started i.e. my car engine idle dropped, I did a tune-up and had to adjust the throttle body manually, Q – is this the correct way?

Since them approximately every 6 months, I have to manually turn up the idle because it keeps dropping off , even if I clean the throttle body.

Could anybody help me?

[Big Z]

Does your car idle faster on a cold start?
If not, your Idle control valve needs to be serviced, or replaced.
Depending on the length of time it has been down, you may need to replace the ECU as well, as it may have damaged the ECU as well.

[washie]

This car has been used every day for the last 4-5 years, it starts very good in the morning, the IAC valve is not the problem, when it’s hot or in traffic, sometimes the car idles so low that it cuts off. However when the idle screw is adjusted, everything is ok for a couple of months then it drops off again.
Other than that the car has no issues – I really don’t want to start digging in it cuz it’s not a problem as yet. What I would really like to know is, by adjusting the throttle body manually if it will cause a bigger problem in the future, or what is the correct way to increase the engine idle, or is it there something that is going bad that is causing the idle to keep dropping off.

[Big Z]

Your IACV should be able to handle proper idling of the car.
It's not too late to have it properly serviced.
Adjusting the idle screw should not be necessary with a properly serviced IACV.
Idle speed is ECU controlled. It does not need to be adjusted with properly maintenance.

[Hook]

CK2 comes with the 4G13/15 carburettor engine not so? Refresh my memory here.

If it's carb'd, it might be a whole lot simpler than you think (although I hope you eliminated this possibility in the two years you've been experiencing this). Your idle screw might be backing out. Try something for me. Mark the position of the screw next time you adjust it and note if it moved when next it needs adjusting.

If it's EFI, have a scan done to determine if there are any error codes and have the technician inspect your sensor readings and running parameters to ensure everything is within spec.

Outside of that, the only other thing I could think of is if your fuel pump and/or FPR is on the way out.

[washie]

Thank you very much “HOOK”, that was very enlightening, YES! Some of the lancers comes carbureted, my one is a 4G15 double over head cam fuel injected.
On the instrument panel it has an engine check light which comes off every time I start the car. So that should indicate that there isn’t any problems --- right

[Hook]

So it comes off and stays off? Then no error codes...hmmm...

So now I'm really thinking it's either a sensor slowly deteriorating and you keep compensating for it, tho it should've thrown a code by now, OR like I said, fuel pump/FPR that won't throw an error code OR, that screw you keep adjusting is readjusting due to vibration (ah mean, there's only so much you could adjust it before it's either all the way in or all the way out, right?).

[rollingstock]

Sounds like a dirty tb and possible bad iacv, simply spraying throttle body spray don't always properly clean the tb, the tps need to be taken out, the spring checked for tension, tb scrapped and cleaned thoroughly and the iacv has a rubber that seats on the housing of the iacv, normal wear and tear causes a groove to be cut in the rubber and it doesn't seat properly. The ecu will attempt to correct this but it wouldn't last and as big z said can damage the ecu but very rare.

[washie]

Thanks fellers, you all were very helpful; I’ll pass through D bamboo next weekend to see if I can get a throttle body with a TPS and IAC valve