VW Sharan fault

[barnr]

i have a vw sharan P Reg, taken it to the garage today as it comes to a stop for no apparent reason, it may happen after 5minutes use but could go for several hours then stop, it will start again after about 5 mins, the garage cannot find the fault, i have changed the plugs, leads, rotor arm, distributor cap, i am now at a loss to know what else i can do, anyone come across this fault before ? thanks barry

[tonyerc]

Check that your relays above the fusebox are not loose. I would also be obliged if you could advice me what position your relays are in within the fusebox .Each relay has a number clearly marked in white. Ta

[barnr]

Thanks for your help, i have checked the relays one was slightly loose, the numbers are as follows 128 169 53 72 30 18 21 99 36 53 53 167

the van only seems to play up on start up now, i have checked the spark and i have checked that fuel is getting to the plugs, i recently took it to vw specialist who ran a test on the machine on the van and nothing showed up as a fault, thougth they said that as it was not playing up at the time it probably would not show a fault.