I've rebuilt the motor. Stage 1 chip and yellow injectors. New sensors, new TPS new ISCV, new MAP, new twin pumps/filter etc. It ticks over like a sewing machine. 3.5bar fuel with vac pipe off, 3bar on. Revs nice and responsively. Fuel pressure builds as per revs and turbo pressure.

Now, when I try to drive, the motor dies - power drops and it cuts out - even in reverse. Then I can't restart it without "rebooting" the ECU with the cutoff switch. It's kinda like it's being starved of fuel but there is buckets of flow.

Any ideas here please?