so much misinformation. there is no limp mode on an obd1 ecu. you dont use a missing link with a chipped ecu, thats if you have a stock ecu with a piggyback, and if you run that you are doing it wrong. a missing link is a check valve the blocks the map sensor from seeing boost. a stock ecu has no mapping for boost so if it sees positive pressure from the map sensor it freaks out.
you need to get the car tuned asap. it runs like crap because you put a turbo on the car and a random map on a neptune(maybe) chipped ecu.
turbo cars dont need higher fuel pressure. you need properly sized injectors and stock fuel pressure is perfectly adequate. in some occasions higher fuel pressures are in demand but i wont get into that.
what injectors are in the car? what fuel pump is in the car? more info on the setup would be helpful.