900 L4-1985cc 2.0L SOHC (1988)
Fuel Return Line: Customer Interest
Fuel System - Engine Driveability Problems
File IN
S.I. Man.
VOLUME
I
SECTION
B-2
PAGE
21
SUBJECT:
CORRECTING DRIVEABILITY COMPLAINTS DUE TO EXCESSIVE LINE PRESSURE
ISSUE:
06/89-1152
APPLICATION:
ALL 9000 MODELS, 1988- 900 MODELS
On vehicles with the fuel return line check valve integrated into the fuel line at the tank (Figure 1), it is possible for the rubber flap that acts as the check
valve to become detached and block the return line or the ejector pump . A blocked or restricted fuel return line will cause driveability complaints due to
excessive line pressure. This complaint can be diagnosed by measuring the fuel system pressure with a pressure gauge or the LH Tester. To prevent this a
revised check valve has been introduced into early -M89 production. The redesigned check valve consists of a new lower housing to the return line
fitting and a valve core insert (Figure 2). This check valve may also be used to correct earlier cars.
WARNING!
