Anyone know about TD5 Fuel pressure regulators

Help- Anyone know about TD5 Fuel pressure regulator problems?
TD5 stalls and engine runs uneven at tick over, sometimes backfiring.
Problem started when with the engine stopping when I de-accelerated into a junction or round about.

I'm measuring the fuel pressure at the input to the Fuel Pressure Regulator; at tick over the pressure is oscillating between 3 & 4.5bar, the engine runs lumpy and often stops, sometime with what sounds like a backfire. Lift the revs even a small amount and the pressure sits at 4bar and the engine runs OK, let the engine revs drop back to tick over and the pressure starts oscillating again. Has anyone measured fuel pressure on the regulator input, does this oscillation sound normal?

Alan

Sounds normal to me. The in tank fuel pump is not a sophisticated beast and has no pressure regulation. Pressure should be steady at OUTPUT of FPR at around 4 bar minimum.

I've never really heard a diesel engine properly backfire though as the fuel is not volatile enough. Only thing may be a leaking or sticking exhaust valve ???

Have you checked for the good old oil in the ECU loom/plugs ??? as this causes the symptoms you describe.

Hi, thanks got your reply, yes checked loom for oil and all ok, replaced the injector loom as the plug was broken, replaced the crank shaft sensor just in case and after a number of suggestion started looking at the fuel supply.