Ask Smithy Xtra timing belt replacement

A few days after buying a dual-fuel 2000 NM Mitsubishi Pajero I decided to replace the timing belt. It ran for a few minutes after completing the belt change and idled smoothly while I topped up the coolant, but when I tried to give it a bit of a rev it was slow to build up revs and missed a bit. I tried to clear it and revved to about 4000 rpm and once I released the throttle the revs came down as expected but stopped instead of returning to idle. It hasn't started since. I checked all timing marks and it all lines up still, and tried disconnecting battery to reset ECU and sometimes get a clicking sound from the throttle body. Any ideas would be greatly appreciated.