What I usually recommend for all Proton throttle body '"Earthquake' problem; buy 1no used Toyota air-cond adjustable/ATC, drill & tap a hole at inlet manifold, hook-up the vacuum pipe & problem all solve FOREVER. Can set whatever idling rpm you want.

Better-lol, after BOCOR-BOCOR rpm too high pulak.

Just make the mods as I've explain 'aboved', cost less than $300, after that non of those fellas with the problem ever come back again.

If want to use Toyota FICD than you need to do some mods within your current throttle plastic gears. That alone would recommend to install the drill & tap one directly to the main throttle chamber so as it's distributed to all cyclinders without any possible air-leaks, no cars which have been installed with this current method that I've known of ever had a recurrent of this problem. But some will want to maintain without mods & this is what has been done for its maintainence;

remove throttle-body magnet & do a service every 10K km, by cleaning with non-solvent base cleaners, water base ones & compressed air. Do not use anything like petrol or any alcohol base as it will damage the plastic components. After that apply the cleanest & best water base grease/lubricant that money can buy no other than 'KY' which can be obtain from pharmacy. Seal the item again with silicone liquid gasket & it'll perform as per new until the next service interval. So far so good for my mates.