OT escort shudder help

[bluestang67]

1994 1.9 L Ford Escort


OK guys i bought this escort and have a stumbler for me . It has a shudder after in OD that only comes in when the temp gage is in the high side of normal . The shudder is pretty violent and if i excelerate a little it goes away or if i let off gas it goees away . If i turn on the heat and drop temp down to lower normal it dont happen at all . I did notice the cooling fan dont come on till it hits the higher side of normal can i get this to turn on sooner with a different or newer relay . Would this be in the tune up at all a mechanic said it sounds like a light load miss fire dirty injectors . It has had new plugs and wires installed by previous owner . To me seems like drive line is shaking maybe trans being hot . I also did inspection and found the 2 inner CV joints slightly worn could this cause a shudder under light loads also .