900 L4-1985cc 2.0L (1982)
Fuel Filler Cap: All Technical Service Bulletins
Engine - Occasional `Jolt' While Driving
SUBJECT:
INTERMITTENT HOT FUEL DELIVERY M80-83-1/2 900 MODELS
ISSUE:
06/84-691
FILE IN S.I. MANUAL:
VOLUME:
I
SECTION:
2
PAGE:
163
Intermittent interruption of fuel delivery during hot ambient conditions has been determined to be caused by deficient Evaporative Control System
pressure. If components of this system are not meeting the original specification, or if the fuel filler cap is not properly tightened, the reduction in
Evaporative System or tank pressure can cause vapor bubbles to form in the fuel and momentarily interrupt or cause a "miss" in the delivery of fuel from
the fuel pump.
The usual symptom of this problem is an occasional jolt which is felt while driving on the highway at steady speed or when depressing the accelerator
slightly such as when climbing a grade in hot, humid weather (above 80~F).
NOTE! In order for the instructions of this S.I. to be effective, the car must be in stock condition, i.e., unmodified fuel pick-up trays, tank pressure valve
in place and CIS pressures and ignition system within specification.
Details on the repair of this occurance are detailed below:
REPAIR PROCEDURES:
1.
Perform a check of the Evaporative Control Pressure system as described in S.I. 05/84-689, Volume I, Sec. 2.
Repair any pressure leakdown faults with the aid of the S.I.
2.
Replace the evaporative system pressure valve (P/N 93-0-462 as per the instructions in S.I. 05/84-689 if it does not open and maintain a pressure
of at least 1.2 psi (0.08 bar) but not more than 2.2 psi (0.15 bar) for at least 5 seconds.