Folks, having encountered all the above symptoms of lag, no power, no
kicking in low revs, 20 mph everywhere in every gear etc etc. I replaced my
valve gave the innards a good clean with carb cleaner etc. and replaced the & Air Flow sensor (£146 total inc Vat from GSF). Same problems, I subsequently found a couple of frayed wires leading to connections just below the
valve, I stripped the conduit back and fixed this with good quality insulating tape, anyhow the problems remained. I bit the bullet and slowly drove to my local independent garage with a diagnostic tester to find the
pressure sensor had an open circuit. New sensor required!!
Top tip dont clean the inside of this sensor with Carb Cleaner!!!!
A friend has the same car so I swapped the sensors around and hey presto! the car has life again thank goodness.
Morale of the story spend £20 with a local garage to diagnose the problem in the first place!!
Oh By the way the
valve needed replacing as it was broken in two on removal and really messy.
I hope this helps someone as I reading all these posts with different cures and diagnosis was really doing my head in.