This is intermittent it always starts but as stated when hot sometimes cranks for up to 10 secs before firing with no codes stored, pre supply (elec pump) is ok at 10psi, tandem pump rises to 60psi nearly before starting but sometimes is only at 45psi when idling (I have not had extended cranking problem with gauge connected) when increasing revs to 4000rpm 105psi is achieved which is correct but it is not always linear to engine speed and sometimes drops back as revs are raised (but never less than it was when idling) the needle sometimes fluctuates quite violently (it was unreadable with Sykes gauge so swopped to Snap On which stabilized it some) I've left the fuel filter out of the canister and at first thought I had tandem pump fault with engine oil in fuel as it was very black but after running with fuel filt out checked in a white cup it's fine, I remem having this fluctuating needle before when testing a tandem pump and stripped it to find broken vane spring but not sure of that vehicles symptoms. So although I have this fluctuating needle the pressure seems ok or do you think this could be the problem, it also doesn't seem to effect it if I clamp the return line to check injector seals. Also drives faultless with no lack of power issues.

As usual sorry for the long post!

Rob