i just got a 89 T2 but it has weird idle. it goes up and down about 750-1000 rpm and sometimes it dies. but it im driving it and keeping the gas pedal down then there is no problem. the boost it good.

 

Well that wasnt TOO hard to read

Obviously you have the "idle problem", which plagues a lot of the members. It cannot be traced to one single cause: usually its a lot of things combined, or it could be any one of the root causes.

Start searching for intake leaks, loose vacuum hoses, gum/dirt/carbon builtup in the intake system, wrong TPS setup, BAC over/under-adjusted etc etc.....