Starting the Volvo Viking with the D67 engine worked good, but after about 30 seconds, the idle started to rise, slow but steady until it peaked out at max rpm.
Turned out the Injection pump diaphragm was broken (some kind of leather)
Ordered a new one from ebay and swapped out, worked perfectly
The pump is a CAV pump where the idle is adjusted throu vacum from the inlet tube in some intricate way, and the huge spring working against the vacum.
Injection pump diaphragm CAV Pumps BPE4A 7034-19H
Leather Type equivalent to CAV Part No: 7034-19H