944 S2 Cabriolet L4-2990cc 3.0L DOHC (1991)
Air/Fuel Mixture: Adjustments
The air/fuel mixture is controlled by the digital motor electronics (DME). The CO-content can only be checked, there are no provisions for adjustment.
1.
Run engine to operating temperature.
2.
Turn engine off.
3.
Remove the test cap at exhaust test port. The test port is located in rear of engine compartment, on RH side next to valve cover.
4.
Connect a suitable CO tester to test port.
5.
Do not disconnect oxygen sensor plug.
6.
Run engine (at operating temperature) and measure CO content at idle. CO content should be 0.8 ±0.4%.
7.
If test results are not correct, check engine for possible vacuum leaks, mechanical or digital motor electronics (DME) failure (see
COMPUTERIZED ENGINE CONTROLS).
8.
Disconnect all test equipment and reinstall the CO test port cap.
