I had almost similar problem with my Wira previously. During cold start, I need to press the accelerator slightly before it can start successfully.

I did a few things to resolve it:

I asked a wireman to service the starter. After that, I asked my foreman to clean the throttle body, replace the fuel filter and change the spark plug from copper to platinum.

When the foreman replace the fuel filter, did he clean the throttle body ? By right he should have done it. The labor charge to clean the throttle body ranges from RM 30 - 50 while the labor charge to change the spark plug is less than RM 15.

For spark plugs, the price can be as cheap as RM 30 for copper based spark plugs while platinum type can cost you around RM 60 - 70.