This started about a week ago now, when I start the car in the morning, it struggles to idle and even stalls every now and then. When I go to take off it drives fine for a few minutes then the car's revs start dropping and the car jumps forwards and backwards like it's trying to change gears or something. The gear changes are also harsh. If I have my cruise control set, it will jump revs and then go back down again constantly. I've even had it stall at 60k's at one point.

It drives fine when it's not cold/in the afternoon though.

Any ideas?

This could be caused from a range of things. 1st thing I would do is look at changing the spark plugs + leads and also give it a service

Did you work on the car before this happened? Might be able to eliminate some things as you back track.

Check your earths and battery terminals. They might be loose, corroded and need a good clean for better contact. Vacuum leaks can cause bad/rough idle.

How old is the battery?

I ask because the battery produces less charge or loses it's storage capacity when cold. Also is it a sealed maintenance free battery or the one with distilled water top up requirement? If it's the latter, check if the fluids are good, low water level and cold weather will definitely reduce storage capacity as well as recharging rate/power supply. Low power supply to the ECU can cause some dramas.

Also is the alternator charging properly?

Another thing to check is ignition, distributor, spark plugs, leads, TFI module. Also your idle speed controller could be bogus causing bad idle/stalling. Give the throttle body a clean and see if that helps with idle.

That might give you a start. Good luck.

forgive the ignorance but whats a tfi module?

the stupid thing on the side of the dizzy. they fuk up all the time.

The battery's a year and a half old, and it's the sealed one. I don't have a spare good battery lying around to test it, however if I can borrow one I'll be sure to test it out.

The belt doesn't squeal so I assume the alternator's working fine.

Dizzy and leads were replaced less than a year ago, how long are they meant to last for? I might change my spark plugs soon as I haven't done them in a while. I'll also clean out the throttle body.

Where's the ISC and is it easy to change?

Cheers guys.