Poor acceleration

i find myself stalling at take off, have to get revs up to pull away. Also having to crank over a few times to start and then erratic till revs build up. Tick over fine once started but lack of power at start up awkward. I'm off to Glastonbury tomorrow for annual mud fest transporting bands and equipment all over Worthy farm and beyond, it will be acutely embarrassing to die down there!
Help!
Ps , have just joined up, Hello

...and what are you driving? Might help.Sounds like your ignition timing is out but its useful to clarify if you have a diesel and what model etc. Glastonbury eh!

Ah yes! It's an ex military 110 with 300tdi . All was fine, only thing I've done
Recently is an oil change. There is a lag before it picks up, resulting in me
stalling when pulling off. I think I will be ok, I shall modify driving style, anyway
I expect to be in low ratio for next week.