Cams are a good idea on these cars - I even had a set on a 1.6 NA 5 sometime ago. Best to read up on the theory of operation as it can be quite a complicated area of modding.just wondering if anyone is using upgraded cams and if they are what make and whered you get em ? had a set on my 205 gti before and made a huge difference
Cams will allow more air in, especially at idle, so if you don't have the ability to fuel the added air the car will run lean at idle hence the erratic idle while the ECU tries to get stoich AFR of 14.7. Not a problem for the aging NA as it is not an MOT issue. The NA also runs very rich at WOT so the cams shouldn't have an issue with fueling.
The main issue is the ECU. The 5's ecu is archaic, so fueling cams will be difficult with the stock ecu.
You'll also need cam gears, degree the cams in and dyno time to get the best out of them. A head shave to match the cams would also be recommended.
When all is said and done and you've spent ???'s you'll get a 10bhp bump at best, more than likely less. Best to save your cash and go FI.