Coffee,
Something went wrong with my set-up a few weeks ago and it went into limp mode.
If the van's in limp mode it will perform a bit like it did when it had the original engine.
In limp mode the engine is flat. Hard to describe but it's gutless, won't rev and consumes quite a bit of fuel. My car weighes 1600kg with pretty low diffs so when it's on song the rush from 3,000 rpm to 6,000 in first is pretty impressive. When off song you could almost run faster than it. It even sounds sick, not crisp and willing.
I couldn't find the fault in any sensor, so on Saturday I took to the wiring with cutters and removed all the wiring for the ECU. Drastic but I'd had enough. By Sunday afternoon it was all back together with neat looms running to/from the ECU and relays with it all mounted on a hinged alloy panel for ease of access. Now it runs beautifully. Still uses heaps of fuel but I think that's my right foots fault.