Non-Trouble Code Procedures

Fig. 80 Vacuum Supply Test:

1. Disconnect vacuum hose at servo and install a suitable vacuum gauge in the hose.
2. Start engine and observe gauge at idle. Vacuum should read at least 10 inches of mercury. Shut off engine and ensure vacuum holds.
3. If vacuum does not meet the above requirements, check for leaks in vacuum lines, check valve, vacuum reservoir or poor engine performance.