Auxiliary Air Regulator

On 1975-77 models, disconnect airflow sensor connector. This isolates the safety circuit and allows fuel pump to run with ignition ON and engine not running.
On 1978-79 Volvo, connect Test Relay (5170) to ignition coil. On 1978-79 Saab, connect jumper wires to fuel pump circuit. See TEST EQUIPMENT HOOK-UP in this article.
On 1975-77 Volvo, disconnect positive wire at alternator and remove vacuum hoses from auxiliary air regulator. On all models, unplug control pressure regulator connector.
Using a mirror and flashlight, check to see that air passage in regulator is open (cold engine). See Fig 1. Turn ignition on and reconnect auxiliary air regulator vacuum hoses (if removed). Air passage in regulator should close after 5 minutes. If not, replace auxiliary air regulator.

Fig 1: Checking Auxiliary Air Valve Opening
Courtesy of NOT AVAILABLE