Boost Pressure

NOTE: Conditions under which testing must be performed are as follows: There should be no leaks on intake or exhaust fuel side, boost pressure is to be measured with engine at full throttle during road test or on dynamometer, and test time per measurement should not exceed 10 seconds.

Disconnect connection hose between intake pipe and fuel injection pump. Connect hoses together with "T" fitting from pressure gauge (V.A.G. 1397).
Lay pressure gauge down on passenger seat or squeeze gauge between windshield and dash, but DO NOT allow vacuum hose to be squeezed between engine hood and body.
Open gauge stop valve by pushing toward gauge. Measure boost pressure with engine at full throttle.
If testing is being done on a dynamometer, engine should be run at 4000 RPM and should be in 3rd gear with manual transmission, or 2nd range with automatic transmission.
If testing is being done by road test, vehicle speed should be maintained at 35 MPH, using service brake. Manual transmission models should be in 2nd gear and automatic transmission models should be in 1st range.
Read boost pressure on gauge. See BOOST PRESSURE table. To make boost pressure reading easier to read during road test, pull gauge stop valve away from gauge; this will maintain reading on gauge.
If boost pressure is too high, wastegate is defective and replacement of turbocharger is necessary.
If boost pressure is too low, disconnect blow-off valve hose from intake air hose, plug air hose with a 1" (25 mm) plug. Tighten with clamp and repeat boost pressure test. If boost pressure is correct, replace blow-off valve. If boost pressure is too low, replace turbocharger.

BOOST PRESSURE

Application	psi (kg/cm² )
All Models	9-10 (.63-.70)