Vr calais 5l missing

[vrcalais5L]

I've got a Vr calais 5L and about 4-5 months ago it started running like a dog, missing shuddering doin all sorts of ****. During that period it was put on gas and I was told it had nothing to do with it. I changed da plugs, dizzy cap and rotor, an got da same mechanic to have a look he reckon it mighta been a weak coil, nahh that didnt fix up da prob. So I got the heads recod thinking it fix the miss but it keep on running sht. Now Ive been told 5 litres are common for there cam lobes to go, I was thinkin are bottom end rebuild but anyone got any ideas what it could be any help is appreciated?

[undar8ed1]

Obvious but I`d thought I`d mention it, spark plug gap, is it gapped properly for gas?

[vrcalais5L]

yehh i dropped em .1 of a mm for gas didnt seem to make a difference

[vsv8berlinawag]

Might be your ignition module ? The age of these 5 litres are now getting on and these modules have a trend of breaking down causing all sorts of missing issues and rough idling. Does your tacho jump around when its playing up ?