Bad Idling / Stalling Etc....

Hi.

My 1997 (P) Laguna 1.8 has been almost perfect till now. Its done 140,000 almost now and has developed the following...

Although it still starts first time, it doesn't have the normal sharp idle speed associated with older cars (choke). I know the ECU controls this but the high idle is not present until I blip the throttle and then it idles ok.

However, once it has warmed up, the car idles at about 500 - 600rpm and when trying to move off, the car stalls. I have also noticed that when I rev it from idle, the revs dip slighly lower and there is a pinking noise before the revs pick up.

The clutch biting point is nearest the top right now so I'm thinking the clutch is on it's way out (but it does not slip at all, not in the slightest).

Most of the above started after the battery ran flat (no fluid in the battery). The battery seems to be ok but its still the same battery, so could this be playing havoc with the idle? Anyway to test this before I replace it?

Also, the stalling of the car, I think it's probably related to the low idle and although it will need a clutch soon, I think if I could sort out the idle it may give the clutch a better chance?

Any insights would be greatly appreciated...

Idle speed is normally controlled by monitoring the TDC (Top Dead Centre) Sensor which is usually mounted somewhere on the flywheel. It could be a dodgy connection there.

Also - have you had the cam belt changed? Even if you have it could be the cam belt pre-tensioner is slack allowing excess play in the belt. This will effect valve and ignition timing.

Given the symptoms you describe, these may be worth checking out.

Regards

ER

Thanx for that EwanR.

I was told that the ECU needs to relearn its settings and that i should run it at fast idle for about 10 mins and that would sort it. Indeed I tried it once and it did sort it.

Now, however, I had to replace the battery and the same is true again with the very low idle etc. However, now the fast idle etc just don't work to cure it like it did the last time.

The cambelkt was last changed about 3 years ago and maybe it is due but I don't think it is that. But i will get the pre-tensioner checked as well as the connections at the TDC.

Thank you.