Prelude L4-1829cc 1800 ES,ET (1983)
2.
Start engine and run until it reaches operating temperature.
3.
Ensure that there is vacuum at idle. If so, disconnect vacuum gauge and reconnect hose.
4.
If vacuum is not available, pinch hose between thermovalve and air filter and, if vacuum is now available, replace thermovalve.
5.
If vacuum is not available when pinching hose in step 4, check for leaks or blockage in hoses 7 and 19 on all 1982 and 1983 Civic and Accord,
hoses 17 and 19 on 1983-86 Prelude and 1984-86 Civic, hose 18 on 1984 Accord and hose 19 on 1985-86 Accord.