Hi all,
I have a 1992 Sierra 4x4 cossie and she won't boost over 0.4 bar and that's with the actuator rod wound all the way in. i have replaced the actuator the amal valve the spark plugs the dizzy cap.I took the turbo off and sent it to a specialist and he said there was nothing wrong with it. Please please please can someone help me as I'm about to pull my hair out and i can't afford to lose any more hair.

Thanks all.