(T) Jtd engine light mystery

hi, posting this as no one on the Marea forum can help.

I have a 105 Jtd Weekend with the following problem,

Engine light comes on if you rev the car over 3,500 rpm before it has fully warmed up. Once the light is on you cant rev the engine more than 3,500 rpm. The engine performance then slowly improves until the light eventually goes off and all is normal again. Once the engine has warmed up (2 clicks from relays near passenger foot well) you can rev it as much as you want without the light coming on. This has foxed my mechanic and he is currently researching it. The car went for an on road diagnostic so the fault could be reproduced and recorded on his diagnostic equipment. The fault recorded was "Boost Pressure"

His test's have shown that the turbo is not over boosting but he dose'nt understand why it's only doing this when the engine is warming up?

Can anyone shed any light on this?? __________________

Waste gate sticking causing exhaust to bypass turbo? How does it drive when its warming up, sluggish with no turbo? Also try pulling the maf sensor connector off. Do strange things when they are faulty.

Car drives fine when it's warming up, also if you remove inlet pipe that feeds air filter you can hear turbo dump valve working?

Have finally sorted this problem, split in the inlet hose from MAF to turbo. The light problem is now sorted and a few more horses have appeared under the bonnet.

however, I now have a new light fault, First time car is used after about 5 miles light comes on when revs drop, light goes out as revs rise dose this al the time then while driving, stop the car and leave for 10-20 minuets and when the car is restarted light comes on, drive off and rev it to 3250 light goes out and stays out? If you are doing motorway driving light is on and off more times than tarts knickers. Unlike the other fault the car still drives fine and dosn't go into limp home mode, any idea's?