2.3 Turbo t-bird 1988 running on 3 cyl until boost

[thundercluck]

Hi I have an 88 thunderbird Turbo coupe it's o ly running on 3 cylenders until I hit boost then its all there I have replaced wires plugs cap rotor compression is 145psi on cyl 1 148 cyl 2 ad 150ish on 3n4 I ha e my timing at around 18degree anything less then that and it hates boost period and pops out the exhaust any help would be awesome it's all stock motor is from an 86 tc with all the 88 attachments like intercooler and ecu and sutch

[Stinger]

When you're checking compression, are you pulling one spark plug at a time or removing them all before testing?