2006 chassis cab - intermitent power at 3000rpm

[mattcooper]

Hi - wondered if anyone could help with the following - got a 2006 115bhp (low ratio gearbox) T350 chassis cab fitted with Luton body - it's on 95k miles and has aleady had a minor engine rebuild (one of timing chain cogs fell off at around 70k), a new clutch/gearbox and more recently a new rear back axle (reckon this one was a Friday afternoon job - got 4 other tranists on fleet which run like a dream). Just after back axle was fitted driver reported a problem where the revs were uneven around 3000rpm (but fine throughout rest of rev range), almost as if fuel supply was irregular. Unfortunately, as it's the low ratio gearbox version, 3000rpm is motorway cruise speed, and this also causes problems going up hills. I use a local Rapid Fit place in Taunton for all our vans and can't fault them. However, they have no idea about this one. It's been to local main dealer as well, and their diagnostics computer isn't bringing up any faults. Got main dealer's chief mechanic (who's been with Ford for 30 years) baffled too. We've run a few tanks of fuel through it so it's not dodgy diesel, we've checked turbo (one pipe had a slight split but that has been replaced and made no difference). We've tried a new intercooler but that didn't work. All the other parts you'd normally look at (fuel pump, fuel lines, glow plugs, etc) would cause the problem throughout the rev range, but this only happens at 3000rpm. And so we've come to a dead end - apart from taking it apart and rebuilding the engine (again) we don't know what to do next. Anyone any ideas? Has anyone come across this problem before? Would be very grateful for any help.
Matt C

[MrMPuk]

Probably EGR.

[mattcooper]

Sorry taken a while to respond - been away with work. Already tried EGR valve, and another valve which I can't remember abbreviation for. Now had turbo, intercooler, rear axle and diff, exhaust and fuel lines checked, and all fine. Diagnostics computer still showing no faults. Next line of enquiry is fuel pump and injectors, but am reluctant to start chucking that kind of money at it when it's not certain that will rectify problem. Anyone any ideas?

[AndyG]

PCM update

[winterheating]

is this one a mk6 or 7