1982 CHEVROLET CAMARO Repair Guide

GM – CAMARO 1982-1992 – Repair Guide (Checked by WxMax) 625
1990-1992 5.0L AND 5.7L TUNE
D PORT INJECTION

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ENGINE PERFORMANCE AND TUNE-UP

TUNE-UP PROCEDURES
In order to extract the full measure of performance and economy from your
engine it is essential that it is properly tuned at regul ar intervals. A regular tune-
up will keep your Camaro's engine running smoothly and will prevent the
annoying breakdowns and poor perform ance associated with an untuned
engine.
A complete tune-up should be performed every 30,000 miles (48,000 km). This
interval should be halved if the car is operated under severe conditions such as
trailer towing, prolonged idling, start-and- stop driving, or if starting or running
problems are noticed. It is assumed that the routine maintenance described in
General Information & Maintenance has been kept up, as this will have a
decided effect on the result s of a tune-up. All of the applicable steps of a tune-
up should be followed in order, as the result is a cumulative one.
If the specifications on the underhoo d tune-up sticker in the engine
compartment of your car disagree with th e "Tune-Up Specifications" chart in this
Section, the figures on the sticker must be used. The sticker often reflects
changes made during t he production run.
SPARK PLUGS
A typical spark plug consists of a metal shell surrounding a ceramic insulator. A
metal electrode extends downward through the center of the insulator and
protrudes a small distance. Located at the end of the plug and attached to the
side of the outer metal shell is the side el ectrode. The side electrode bends in at
a 90 angle so that its tip is just pas t and parallel to the tip of the center
electrode. The distance between these two electrodes (measured in
thousandths of an inch or hundredths of a millimeter) is called the spark plug
gap.
The spark plug does not pr oduce a spark, but instead provides a gap across
which the current can arc. The coil produces anywhere from 20,000 to 50,000
volts (depending on the type and application) which travels through the wires to
the spark plugs. The current passes along the center electrode and jumps the
gap to the side electrode, and in doing so, ignites the air/fuel mixture in the
combustion chamber.

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Fig. 1: Cross-secti on of a spark plug

Fig. 2: A variety of tools and gaug es are needed for spark plug service

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SPARK PLUG HEAT RANGE
Spark plug heat range is
the ability of the plug to dissipate heat. The longer the
insulator (or the farther it extends in to the engine), the hotter the plug will
operate; the shorter the insulator (the cl oser the electrode is to the block's
cooling passages) the cooler it will operate. A plug that absorbs little heat and
remains too cool will quickly accumulate deposits of oil and carbon since it is
not hot enough to burn them off. This leads to plug fouling and consequently to
misfiring. A plug that absorbs too much heat will have no deposits but, due to
the excessive heat, the electrodes will burn away quickly and might possibly
lead to preignition or other ignition probl ems. Preignition takes place when plug
tips get so hot that they gl ow sufficiently to ignite the air/fuel mixture before the
actual spark occurs. This early igniti on will usually cause a pinging during low
speeds and heavy loads.

Fig. 3: Spark plug heat range
The general rule of thumb for choosing the correct heat range when picking a
spark plug is: if most of your driving is long distanc e, high speed travel, use a
colder plug; if most of your driving is stop and go, use a hotter plug. Original
equipment plugs are general ly a good compromise between the 2 styles and
most people never have the need to change their plugs from the factory-
recommended heat range.
REMOVAL & INSTALLATION
A set of spark plugs usually requi res replacement after about 20,000-30,000
miles (32,000-48,000 km), depending on y our style of driving. In normal
operation plug gap increases about 0.001 in. (0.025mm) for every 2500 miles
(4000 km). As the gap increases, the plug' s voltage requirement also increases.
It requires a greater voltage to jump t he wider gap and about two to three times

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as much voltage to fire the plug at hi
gh speeds than at idle. The improved
air/fuel ratio control of modern fuel injection combin ed with the higher voltage
output of modern ignition systems will often allow an engine to run significantly
longer on a set of standard spark plugs, but keep in mind that efficiency will
drop as the gap widens (along wit h fuel economy and power).
When you're removing spark plugs, work on one at a time. Don't start by
removing the plug wires all at once, because, unless you number them, they
may become mixed up. Take a minute before you begin and number the wires
with tape.
1. Disconnect the negative battery cabl e, and if the vehicle has been run
recently, allow the engine to thoroughly cool.
2. Carefully twist the spark plug wire boot to loosen it, then pull upward and
remove the boot from the plug. Be su re to pull on the boot and not on the
wire, otherwise the connector locat ed inside the boot may become
separated.
3. Using compressed air, blow any water or debris from the spark plug well
to assure that no harmful contam inants are allowed to enter the
combustion chamber when the spark plug is removed. If compressed air
is not available, use a rag or a brush to clean the area.
Remove the spark plugs when the engine is cold, if possible, to prevent damage
to the threads. If removal of the plugs is difficult, apply a few drops of
penetrating oil or silicone spray to t he area around the base of the plug, and
allow it a few minutes to work.
4. Using a spark plug socket that is equipped with a rubber insert to
properly hold the plug, turn the spar k plug counterclockwise to loosen
and remove the spark pl ug from the bore.
WARNING - Be sure not to use a flexible extension on the socket. Use of a
flexible extension may allow a shear fo rce to be applied to the plug. A shear
force could break the plug off in the cylinder head, leading to costly a\
nd
frustrating repairs.
To install:
5. Inspect the spark plug boot for t ears or damage. If a damaged boot is
found, the spark plug wire must be replaced.
6. Using a wire feeler gauge, check and adjust the spark plug gap. When
using a gauge, the proper size shoul d pass between the electrodes with
a slight drag. The next larger size should not be able to pass while the\

next smaller size should pass freely.
7. Carefully thread the plug into the bor e by hand. If resistance is felt before
the plug is almost completely th readed, back the plug out and begin
threading again. In small, hard to r each areas, an old spark plug wire and
boot could be used as a th reading tool. The boot will hold the plug while
you twist the end of the wire and t he wire is supple enough to twist
before it would allow t he plug to crossthread.

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WARNING
- Do not use the spark plug socke t to thread the plugs. Always
carefully thread the plug by hand or us ing an old plug wire to prevent the
possibility of crossthreading and damaging the cylinder head bore.
8. Carefully tighten the spark plug. If the plug you are installing is equipped
with a crush washer, seat the plug, then tighten about
1/4 turn to crush
the washer. If you are installing a t apered seat plug, tighten the plug to
specifications provided by the vehicle or plug manufacturer.
9. Apply a small amount of silicone di electric compound to the end of the
spark plug lead or inside the spark pl ug boot to prevent sticking, then
install the boot to the spark plug and pus h until it clicks into place. The
click may be felt or hear d, then gently pull back on the boot to assure
proper contact.
INSPECTION & GAPPING
Check the plugs for deposits and wear. If they are not going to be replaced,
clean the plugs thoroughly. Remember t hat any kind of deposit will decrease
the efficiency of the plug. Plugs can be cleaned on a spark plug cleaning
machine, which can sometimes be found in service stations, or you can do an
acceptable job of cleaning with a stiff br ush. If the plugs are cleaned, the
electrodes must be filed flat. Use an igni tion points file, not an emery board or
the like, which will leave deposits. The electrodes must be filed perfectly flat
with sharp edges; rounded edges reduce the s park plug voltage by as much as
50%.
Check spark plug gap before installati on. The ground electrode (the L-shaped
one connected to the body of the plug) mu st be parallel to the center electrode
and the specified size wire gauge (please refer to the Tune-Up Specifications
chart for details) must pass between t he electrodes with a slight drag.
NEVER adjust the gap on a used platinum type spark plug .
Always check the gap on new plugs as they are not always set correctly a\
t the
factory. Do not use a flat feeler g auge when measuring the gap on a used plug,
because the reading may be inaccurate. A round-wire type gapping tool is the
best way to check the gap. The co rrect gauge should pass through the
electrode gap with a slight drag. If you're in doubt, try one size smaller and one
larger. The smaller gauge should go through easily, while the larger one\

shouldn't go through at all. Wire gapping tools usually have a bending tool
attached. Use that to adjust the side electrode until the proper distance is
obtained. Absolutely never attempt to bend the center electrode. Also, be
careful not to bend the side electrode too fa r or too often as it may weaken and
break off within the engine, requiring remova l of the cylinder head to retrieve it.

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Fig. 4: Checking the spark plug gap with a feeler gauge

Fig. 5: Adjusting the spark plug gap

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Fig. 6: If the standard plug is in good c ondition, the electrode may be filed flat -
WARNING: do not file platinum plugs