use this code
#include <RTL.H>
#include <LPC17XX.H>
#include <Ports.H>
#include <LCD.H>
#include <uart.h>

static char in_line[160];
int pos = 0;

int i;


void ComProc()
{
    myLog((u8*)&in_line,3);
  if ( strcmp(in_line,"cls") == 0)
    cls();
  for ( i=0; i < 160; i ++ )
  in_line[i]=0;
  pos = 0;
}

void EnableCntr0()
{
    //Set PINSEL3 [21:20] = 11 for P1.26 as CAP0.0
     LPC_PINCON->PINSEL3 |= (0x3 << 20);

  // set pin P1.26 as input
  LPC_GPIO1->FIODIR &=~(1<<26);

  // PCTIM0 Timer0/Counter0Power On
  LPC_SC->PCONP |= 2;

  // Counter Reset
  LPC_TIM0->TCR = 2;

  //Counter Mode:TC incremented on rising edges on the CAP0.0 for
  // timer0
  LPC_TIM0->CTCR = 1;

  // Capture on rising edges on the CAP0.0.
  // TC -> CR0
  LPC_TIM0->CCR = 0;

  // Counter Enable.
  //LPC_TIM0->TCR = 1; // I try 1 too and it still does not work
  LPC_TIM0->TCR = 1;  // 0=Enable from data sheet
}

void EnableCntr2()
{
  //Set PINSEL0 [9:8] = 11 for P0.4 as CAP0.0   --->p0.5 ;ar mikonad
   LPC_PINCON->PINSEL0 |= (0x3 << 8);

  // set pin P0.4 as input
  LPC_GPIO1->FIODIR &=~(1<<4);

  // PCTIM0 Timer1/Counter0Power On
  LPC_SC->PCONP |= 2;

  // Counter Reset
  LPC_TIM2->TCR = 2;

  //Counter Mode:TC incremented on rising edges on the CAP2.0 for
  // timer1
  LPC_TIM2->CTCR = 1;

  // Capture on rising edges on the CAP0.0.
  // TC -> CR0
  LPC_TIM2->CCR = 0;

  // Counter Enable.
  //LPC_TIM0->TCR = 1; // I try 1 too and it still does not work
  LPC_TIM2->TCR = 1;  // 0=Enable from data sheet
}


void EnableTimer2()
{
  //Set PINSEL0 [9:8] = 11 for P0.4 as CAP0.0   --->p0.5 ;ar mikonad
   LPC_PINCON->PINSEL0 |= (0x3 << 8);

  // set pin P0.4 as input
  LPC_GPIO1->FIODIR &=~(1<<4);

  // PCTIM0 Timer1/Counter0Power On
  LPC_SC->PCONP |= 2;

  // Counter Reset
  LPC_TIM2->TCR = 2;

  //Counter Mode:TC incremented on rising edges on the CAP2.0 for
  // timer1
  LPC_TIM2->CTCR = 0;

  // Capture on rising edges on the CAP0.0.
  // TC -> CR0
  LPC_TIM2->CCR = 0;

  // Counter Enable.
  //LPC_TIM0->TCR = 1; // I try 1 too and it still does not work
  LPC_TIM2->TCR = 1;  // 0=Enable from data sheet
}


void EnableCntr1()
{
//Set PINSEL3 [5:4] = 11 for P1.18 as CAP1.0
 LPC_PINCON->PINSEL3 |= (0x3 << 4);
//LPC_PINCON->PINSEL3 |= (0x3 << 7);

// set pin P1.18 as input
LPC_GPIO1->FIODIR &=~(1<<18);
LPC_GPIO1->FIODIR &=~(1<<19);

// PCTIM0 Timer1/Counter1Power On
//LPC_SC->PCONP |= 2;

// Counter Reset
LPC_TIM1->TCR = 2;

//Counter Mode:TC incremented on rising edges on the CAP0.0 for
// timer0
LPC_TIM1->CTCR = 1;

// Capture on rising edges on the CAP1.0.
// TC -> CR0
LPC_TIM1->CCR = 0;

// Counter Enable.
//LPC_TIM0->TCR = 1; // I try 1 too and it still does not work
LPC_TIM1->TCR = 1;  // 0=Enable from data sheet
}


int main()
{
  char c=0;
  u8 prn[100];
  int cntr0;
  int cntr1;

  int cntr2;
  //const unsigned long TCR_COUNT_RESET = 2, TCR_COUNT_ENABLE = 0x01;

  SystemInit();
  LPC_GPIO2->FIODIR |= 0xFF; // P2[0..7] =

  LCD_Init();

  LcdLog = 1;

  LCD_Clear(White);
  LCD_SetBackColor(Red);
  LCD_SetTextColor(Blue);


  UART2_Init();
  logstat=1;
  myLog("Started...",1);
  myLog("LCD--->OK",2);
  myLog("Start UART2",3);
  Uart2Log =1;
  myLog("UART2--->OK",4);
  cls();

  EnableCntr0();
  EnableCntr1();
  //EnableCntr2();
  EnableTimer2();

  while(1)
  {
  cntr0= LPC_TIM0->TC;
  cntr1= LPC_TIM1->TC;
  cntr2= LPC_TIM2->TC;
  sprintf(prn,"%d %d %d %l \n\r", cntr0,cntr1, cntr2);
  UART2_SendString (prn) ;
    c = getkey();
  if ( c != 0 && c != 13)
  {
    in_line[pos++] = c;
    LCD_ShowString(1,19*16, in_line);
  }
  if ( c== 13 )
  {
     ComProc();
  }

  }

}

The counter mode is the wrong mode when you want to measure pulse width 
times. At first, you should get the user manual for the LPC176x, its 
UM10360.
Then you need to configure a timer that runs with a clock with the 
desired resolution of the measurement. If you want 1 µs resolution the 
clock must be set to 1 Mhz.
Then set CCR to capture rising and falling edges and generate an event.
In the ISR, you need to check the input pin if a falling or rising edge 
occured. On a falling edge, save contents of the CR (capture register) 
as start time. On a rising edge, save CR as stop time and add the 
difference to a sum counter.
For the same counter, you can program a MATCH register with a value of 
30e6 and create another interrupt. This will fire after 30 s for the 
final calculation of on-off times.

this condition will never become true:

1

   if((LPC_TIM0->IR & (1<<4)) == 0x01) // if MR0 interrupt

2

3

   // try this:

4

   if((LPC_TIM0->IR & (1UL<<4))) // if MR0 interrupt

Also it is no good idea to use printf() in an ISR. For testing it may 
work, but depends on the code for the output device. It is better to 
collect the results in an array and print that in the main().
But at least the interrupt indicator LED1 should toggle on the capture 
interrupt.