Adjusting the boost pressure requires the disassembly of the diaphragm housing. After the initial adjustment, the car must be test driven to check the results. During the check, it may be more convenient to assembly the housing and hold it together with two small c clamps instead of all the bolts. This will make further adjustments a bit faster should the pressure still be out of specifications.

 

Adjustments are made by turning the upper spring seat. You must make sure the spring is properly seated. Position the lower end of the coil spring at 6 o'clock.

If you have to disassemble the wastegate, an initial spring height adjustment of 18-19 mm will get to close to a pressure within specifications. You can test drive and fine tune it from there.

Use this table after you establish your initial boost pressure to adjust to within specifications.

 

 

If the wastegate valve sticks or binds in the housing, you may solve the problem by cleaning the valve. On these models the valve for the wastegate is very similar to a regular engine valve. It is prone just as they are to burning or deposits build up. Any time you have the assembly apart, it is a good idea to give the valve a good cleaning and inspection. Start by dousing the assembly with a penetrating oil just as WD-40. Tap the end of the valve with a soft hammer to free it up. Loosen the bellows tube and remove the valve and guide. (You can count the turns or just use the 18-19 mm setting to reassemble) Clean the valve with a wire brush. If its seating areas are pitting, you may try lapping it in. If it is bad, you may need to have it ground or replaced. Clean the valve guide with a wire brush and carb clean. Steel wool makes a good polisher for the stem of the valve. A good hi temp synthetic grease for lube on the valve stem will work well. Make sure the valve moves smoothly and easily in the guide.