Oh boy....

How did you set the cam timing? Did you use the factory specs for 2mm of valve lift? Do you have a 603 engine manual?

R&R of the IP on a 603 requires several special service tools - Do you have them?

You must remove the vacuum pump on the front of the engie to access a 17mm bolt that hold the IP to the injection timer. This bolt is a reverse thread set-up, turn to the right to remove it.