new to making jam and preserves

I've just made another batch of bean chutney but added sultanas and tomatoes this time and when i make jam i find the lemon juice  enough to set it   

Pumpkin and orange jam sounds lovely, would like yr recipe Pam? Let us know how it turns out? Can anyone tell me if i can add sugar to my pickling vinegar, i used val's recipe for pickled red cabbage which my hubby loves but my son says the vinegar i got was too strong, i bought ready made spiced vinegar but it doesnt say what strength it isunfortunately. My son says to add some sugar? I sterilised the jars and warmed the vinegar to dissolve the sugar, i addedabout 2 tablespoons to about 1.5 pints of vinegar which once dissolved i poured over the prepared cabbage,am hoping this will pickle ok, can anyone advise please?

I was wondering whether it affected the preserving quality in any way if adding sugar? 

Yes have never added anything else artificial never needed too  must be doing something right