Intermittent starting ...now have fault codes

hi all

Today my 2004 1.9 has developed a shake/vibration on startup..

It's not mechanic (engine as such) more like when the key is turned and it cranks it shakes the van for a second or so quite violently.

I've just reconditioned the head and all the usual and its ran fine for over a week now. There's been on change in performance since this happened

I checked the top engine mount but all was tight

Any ideas? Starter maybe?

Thanks .