top end set up is very cheap in volvos not a big job rocker box cover of turn the engine over till the the correct piston number comes up on the cam it is marked at the front of the cam 1 2 3 etc and on the front bridge that holds the cam in place there is 2 marks the mark on the cam has to be between the 2 marks then set your inlet valve and ajust your preload on the injector careful witch injector you have lucas or bocsh the ajustments are different the exaust clearances are shimed but rarely go out sounds like fuel presure volvo sell a kit for the fuel pump which includes a new return valve etc these are fitted in the bottom of the pump get underneath look up and you will see a nut in the bottom of the pump unscrew slowly as it has a spring and valve in side if the seat on the valve is damaged change it the kit is buttons about 18 pound people fit new pumps when often this is all thats needed also try boost sensor it is in the inlet manifold if this is the problem it should show on dash computer go into diagnostics then engine they are quite expensive i think about 140 after discount and go and buy a 2nd hand diff cos that one is completly wrong iv owned about 10 fh 380 420 460 but never had one geared that low second hand diff about 750 would bring you up to 8 mpg soon pay for its self any way chap good luck
Thanks Keith. Got the go ahead to take to MDF in Gt Yarmouth. They have all the gear. Apparantly even Volvo use them. Pity they didnt scrap the FM380. COULD USE THE DIFF. The FM has cost an arm and a leg in the last 6 months. ECU went first. With call out and a tow, about 4k. New clutch after that, exchange steering box, another high pressure pump, new linings and drums front and rear. Must have spent close to 7k. Truck is14 years old. Still hasnt cost gardy a bean in the 4 @ half years before that.
Will keep you informed
atb
keith the thief:
top end set up is very cheap in volvos not a big job rocker box cover of turn the engine over till the the correct piston number comes up on the cam it is marked at the front of the cam 1 2 3 etc and on the front bridge that holds the cam in place there is 2 marks the mark on the cam has to be between the 2 marks then set your inlet valve and ajust your preload on the injector careful witch injector you have lucas or bocsh the ajustments are different the exaust clearances are shimed but rarely go out sounds like fuel presure volvo sell a kit for the fuel pump which includes a new return valve etc these are fitted in the bottom of the pump get underneath look up and you will see a nut in the bottom of the pump unscrew slowly as it has a spring and valve in side if the seat on the valve is damaged change it the kit is buttons about 18 pound people fit new pumps when often this is all thats needed also try boost sensor it is in the inlet manifold if this is the problem it should show on dash computer go into diagnostics then engine they are quite expensive i think about 140 after discount and go and buy a 2nd hand diff cos that one is completly wrong iv owned about 10 fh 380 420 460 but never had one geared that low second hand diff about 750 would bring you up to 8 mpg soon pay for its self any way chap good luck
I had a feeling you’d post on this one Keefy, I can remember you setting up Two Way Micheal’s TurboStar in Dover, you were wandering back to your motor after a shower and he fired it up as you walked past and it sounded like a bag of bolts, 5mins later it was running like a dream and you heading off for your second shower of the day 
Hi all a quick update.
Fh went to Mdf.
Firstly the air filter was totally clogged. They said they would have no idea when it was last looked at it was so bad.
The same for the fuel/water seperator. This was so bad that it broke up when they took it off.
The fuel stack in the tank, the filter at the bottom was clogged.
They said it was amazing it ran at all.
The valve clearances were way off to.
It runs very well now, BUT still does not pull aswell as the Fm
Further problems.
Drove it back to the yard. About 30 clicks. Noticed a bit of noise from the clutch area. Thrust bearing i thought. With 50 clicks more i am guessing the thrust bearing exploded. I was stationary at the time.
What a pile.
Boss it throwing serious money at these two crocks. I told him to update a year ago. He just says “keep em going” Fm has cost £7500 in the last 6 months on a 98 reg. Been round the clock.
MADNESS UTTER MADNESS.