Air Pump Removal Question

[Tintin]

I\'ve been meaning to ask this for a while but kept forgeting

When I removed the air splitter box thingy I thought I\'d just unplug the airpump untill I got round to removing it , anyway car seemed to run fine but as I went to fill up the engine started hunting on idle , this I could live with however as I pulled out of the petrol station the hunting was getting worse then it just stalled , started it back up went a bit further and it stalled on idle again , plugged the airpump back in and everything was fine running sweet again

Any ideas what the problem is do you need to alter the map ?? can\'t see why you would need to , I could do with finding out why this happened as I\'m a little aprehensive to remove the pump at the mo