Citroen nemo 1.3 hdi engine issue

[prowlise]

After some advise on a Citroen nemo 1.3 hdi Have carried out a timing chain and rocker replacement following a timing chain tensioner fail . All turns over nice timing marks line up once turned over twice again however as soon as I fit the timing cover and oil pump then fit the drive through to the crank and torque the engine becomes incredibly tight to turn over to the point the starter won’t turn it over . It’s already got a new oil pump as was damaged due to the chain is there something I’m missing I can’t see why it should go so tight as soon as the oil drive goes in If I then take the pump of this turns over easily with your fingers and then just put the drive on the crank with the pump of it all turns over well again including on the starter
I have also now tried a new oil pump drive
Any advise appreciated Regards

[mickthemaverick]

If I understand you correctly you are saying that the oil pump rotates freely and the engine without the pump turns normally but when you fit the oil pump the engine goes tight? If so I wonder if this is a shim issue, is the oil pump going too far into the engine? Just a thought