VW Transporter won't start
 

Hi, I'm not a mechanic myself, but am hoping someone can offer a lead on what to try next. We just bought a 1983 VW Transporter camper conversion - 1.9 petrol, watercooled, 4 speed. We drove it 500 miles and back on holiday the week after we bought it, and it was ok. Once we got back home, it wouldn't start again. Thought we'd flooded it but no joy next day either. Starter turns and turns but engine won't fire. Plenty of petrol in it. AA mechanic said there was no spark, and suspected ignition module. Coil lead was burnt out in top of distributor cap. So we bought a new cap, a new lead, and a new ignition module. Other spark plug leads fairly new and in good condition. So we have fitted all that, and it still won't start. As a non-mechanic I know I should probably get one out, but I'd really like to sort it myself if I can. I just don't know what to do next. My Haynes manual doesn't offer any ideas... I wonder if anyone else can?