Sounds like your car is backfiring, a sign that your engine is not well-tuned. If you're from QC or Manila, try to bring your car to Speedyfix along Shaw Blvd in Mandaluyong. The owner there, Migs, will gladly check your car and recommend the fixes to be done. He is a well-trusted shop owner and many tsikot.com members will attest to this. Here is their website: http://www.speedyfixph.com/

One more thing...do not bring your car back to the mechanic who "tuned-up" your car. He was supposed to make your car run better, not the opposite (hard starting).