Porsche 1989 944 S2, Workshop Manual

Page: 121 / 167

944 Air Flow Controlled Fuel Injection
24
Checking idle speed and CO-
with catalytic converter
Model 87 onward
Engine type M 44.40/41 (3.0 l)
Note
It is no longer possible to adjust idle speed
or
CO on vehicles with catalytic converters. The
Lambda probe remains connected while
chekking idle speed and CO.
Checking preconditions
Engine in perfect mechanical condition. Con-
sumers must be switched off during checks.
Carry out checks as quickly as possible to
ensure that the intake paths do not heat up
thus falsifying the CO value. Ambient
temperature 15 - 35° C.
1. Fit standard exhaust adapter to the test
connector of the catalytic converter.
Engine type M 44.40
86/463
Engine type M 44.41 (3.0 l)
173-24
2. Warm engine up to operating
temperature.
(70 - 90° C oil temperature.) Use the oil-
temperature tester, Special TooIs 9122
and 9122/2.
85/114
3. Do not separate the connection for the
Lambda probe. Connect CO tester and
separate speedometer according to the
manufacturer's specifications.
CO reference value 0.4...1.2%
Idle speed 840 +- 40 rpm
Checking idle speed and CO- with catalytic converter
Printed in Germany - XIX, 1989
24 - 105