1998 vitara g16a

[Acidk1]

Hi all

I have my dad's old vitara 1.6 8v spi and it seems to be running lumpy. At low revs you can feel it through the car, I have replaced the dizzy cap and rotar arm, new HT leads, new plugs (old ones where NGK bpr5es but replaced with bpr6es as that's what the Internet generaly seems to recommend) old plugs were nice and grey colour. Also checked pipework for vacuum leaks and set tappet clearences. Adjusted hot idle to about 850rpm and set timing to 4-6 degrees BTDC. Timing belt changed and I double checked it all lined up with the marks yesterday.

The problem has been its quite underpowered at low revs and a bit jerky, and at idle seems to shake the car (almost like it was about to stall, but revs are fine.) once its driving its very nice and will cruise happily at 60-70 mph.

Any suggestions ion what else to check?

Thank you