leisure rangemaster 110 gas grill problem?

hi, my grill is not functioning well it seems to only light a few jets and pops and cracks when lit and as it gets hotter it blows itself out, the jet holes are clean enough so i'm guessing some sort of regulator/pressure problem also it doesn't seem to matter if it's on high or low it just looks like one "level" of gas, the rest is ok apart from sometimes the igniters click even when the oven is lit...