I have this strange problem with my metering unit, when the fuel pressure acuator plug is plugged in (right back hand side of unit) it running like a absolute dog! Clouds of black smoke ect, then when I unplug it, it seems to run perfect! I have changed the wiring loom and it still does it, it's a second hand one I brought for £100 coz my old one was knackered, what is the problem here? Can I get away with running it unplugged at standard boost? What's best to do? And what is at fault here? Please help im stuck on this one.....thankyou

 

Try and get it to a tuner