Oil Spewing 2007 Ford Ranger 3.0 tdci

2007 Ford RangerHi All, i had a cam belt failure, caused damage to values etc, so had head done at engineering shop.
Also refurbished injector pump, fitted 4 injectors(tested and verified ok), replaced copper washers at bottom of injectors and the injector seals.
On start up noticed small oil leak at base of back injector(closest to cab).
We removed the injectors and re-seated the seals, then refitted injectors.
On start up everything ok till we revved, then oil spewing out at base of all four injectors.
Need help please- what can be wrong?



It would seem the wrong seals or washers are being used. Try the old seals and washers as a test.