8051 timer for delay for phase firing angle

[bagusdj]

hey guys, i tried to delay tyristor using timer. i used to use delay(5);. delay(4);, and delay(3); it works, but my LCD that shows adc value is not shows it well. so i want to use timer for delay. my tmod is 0x10. my xtal is 11.0592MHz

but the problem is it seems the tyristor not delayed (thus, my load always run full power. it not happens when use delay()

here is my code. is what am done is wrong for the delay?

void external0_isr(void) interrupt 0 //interrupt routine
{

triac=1;

if((input_port>=10) && (input_port<20))	//1st condition	5ms delay
{
TL1 = 0x00; //Lower Byte
TH1 = 0xFE; //Upper Byte
TR1 = 1; //Run timer
while(TF1==0);
TF1=0;
triac=0;

}
    else if((input_port>20) && (input_port<30))	//2nd condition 4ms delay
      {
	   TL1 = 0x99; //Lower Byte
       TH1 = 0xF1; //Upper Byte
       TR1 = 1; //Run timer
       while(TF0==0);
       TF1=0;
	   triac=0;
	  }
	  else if((input_port>30) && (input_port<40))	//3rd condition 3ms delay
          {
	        TL1 = 0x33; //Lower Byte
            TH1 = 0xF5; //Upper Byte
            TR1 = 1; //Run timer
            while(TF0==0);
            TF1=0;
		    triac=0;
     	   }

          else if(input_port>40) //4th condition; full power no delay
          {
		   triac=0;
		  }
		   else
		    {}
TR1=0;		
}

please help me