Lost with fault

Hi Guys and Girls.

I have a problem with my care idling when cold. Octavia VRS 2001.

The problem started when the car was hot, basically the car was struggling to idle when hot, stopping at the lights the revs would drop for about 10 seconds and then

go back to normal. unfortunately a new fault has occurred but the old one has gone away.

So when I start the car from cold after about 30 seconds the revs drop to 500 and I cant get them back up again, the car struggles like mad. I have to restart the car again and the problem seems to be ok.

Investigating the original fault has prompted me to carry out the following work.

1. Clean the throttle body (I have not yet reset it as I don't have VAG-COM but I read that the ECU does it automatically).

2. Replace the coolant temperature sensor.

3. When replacing the coolant temp sensor I notice the Y shaped hose (Engine breather) had a split so I also replaced that. I thought right that should sort it. It didn't :(

Can anyone suggest my next step. Does anyone have a map or drawing of the hoses I should be checking fro splits or a description (Laymans Terms).

The care does sound terrible when starting in the cold. I think this is down to the rivets sheering on the secondary air pump (I believe this is a common fault) so I plan to do that when I have time and if the weather gets any better.

Any hints/tips would be appreciated and are needed, I'm not afraid to have a go but am not the most informed DIY man.

Cheers GUYS. Oh I have had the car scanned by VAG-COM and the codes can be seen on a previous post if anyone is that interested.

Phil.