Fuel System; Fuel Requirements; Gasoline/Oxygenate Blends - Jeep Wrangler 1997 Manual

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GENERAL INFORMATION
FUEL SYSTEM
CONTENTS
page
FUEL DELIVERY SYSTEM . . . . . . . . . . . . . . . . . . . 3
FUEL INJECTION SYSTEM . . . . . . . . . . . . . . . . . 17
GENERAL INFORMATION
FUEL REQUIREMENTS . . . . . . . . . . . . . . . . . . . . 1
INTRODUCTION
Throughout this group, references may be made to
a particular vehicle by letter or number designation.
A chart showing the breakdown of these designations
is included in the Introduction Section at the front of
this service manual .
The Evaporation Control System, is also considered
part of the fuel system . The system reduces the emis-
sion of fuel vapor into the atmosphere.
The description and function of the Evaporation
Control System is found in Group 25 of this manual .
FUEL REQUIREMENTS
Light spark knock at low engine speeds is not
harmful to your engine . However, continued heavy
spark knock at high speeds can cause damage and
should be reported to your dealer immediately.
Engine damage resulting from operating with a
heavy spark knock may not be covered by the new
vehicle warranty.
In addition to using unleaded gasoline with the
proper octane rating, gasolines that contain deter-
gents, corrosion and stability additives are recom-
mended . Using gasolines that have these additives
will help improve fuel economy, reduce emissions,
and maintain vehicle performance . Generally, pre-
mium unleaded gasolines contain more additive than
regular unleaded .
Poor quality gasoline can cause problems such as
hard starting, stalling, and stumble . If you experi-
GENERAL INFORMATION
INDEX
page
FUEL SYSTEM 1 4-1
page
GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . 1
page
GASOLINE/OXYGENATE BLENDS . . . . . . . . . . . . 1
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . 1
ence these problems, try another brand of gasoline
before considering service for the vehicle .
GASOLINE/OXYGENATE BLENDS
Some fuel suppliers blend gasoline with materials
that contain oxygen such as alcohol, MTBE (Methyl
Tertiary Butyl Ether) and ETBE (Ethyl Tertiary
Butyl Ether) . Oxygenates are required in some areas
of the country during winter months to reduce carbon
monoxide emissions. The type and amount of oxygen-
ate used in the blend is important .
The following are generally used in gasoline
blends :
Ethanol - (Ethyl or Grain Alcohol) properly
blended, is used as a mixture of 10 percent ethanol
and 90 percent gasoline . Gasoline blended with etha-
nol may be used in your vehicle .
Methanol - (Methyl or Wood Alcohol) is used in a
variety of concentrations when blended with
unleaded gasoline . You may find fuels containing 3
percent or more methanol along with other alcohols
called cosolvents .
Do not use gasolines containing Methanol .
Use of methanol/gasoline blends may result in
starting and driveability problems and damage criti-
cal fuel system components.
Problems that are the result of using methanol/
gasoline blends are not the responsibility of Chrysler
Motors and may not be covered by the new vehicle
warranty.
MTBE/ETBE - Gasoline and MTBE (Methyl Ter-
tiary Butyl Ether) blends are a mixture of unleaded
gasoline blended and up to 15 percent MTBE . Gaso-