Color and Condition
|
| Normal Condition without Benefit of Fitch Fuel
Catalyst |
 The
Spark plug to the left is what a normal plug should
look like. Grayish-tan to white in color indicates the
plug is operating at the proper heat range as well as
correct jetting and the cylinder is running healthy.
This plug was operated on a vehicle without a Fitch
Fuel Catalyst. |
|
|
| Normal Condition with Fitch Fuel Catalyst |
 This
is one of four plugs removed from a 1986 GM Cutlass
2.2l. 85,000 miles were accumulated on this plug in
normal driving with regular octane fuel after the Fitch
Fuel Catalyst was installed. Notice the clean electrodes,
absence of carbon, and like new condition. This is evidence
of complete combustion and that the combustion chamber
is clean and like new as well. |
|
|
| Worn Out Condition |
 Excessive
electrode wear, misfire during acceleration and hard
starting. Simply put as in its description, it's worn
out ... it looks ok color wise, so replace it with same
plug or at least compatible heat range. You've all heard
the term "If it works, don't fix it". Don't look for
flaws with this plug ... just blame yourself for not
changing it sooner. |
|
|
| Mechanical Damage |
 Foreign
objects in the combustion chamber or an improper plug
length may cause this if it contacts the piston. Even
a piece of carbon can do this. To solve this, make sure
you have the correct length tip spark plug as well as
removing any foreign materials in the combustion chamber.
In some cases you may have excessive carbon buildup
on the backs of the intake valves that will have to
be addressed. |
|
|
| Detonation |
 In
cases of severe detonation, insulators may become cracked
or chipped. Improper spark plug gap settings will also
cause the insulator tip to crack or chip. Detonation
is tricky... make sure that you are using the correct
octane fuel first and then verify correct ignition timing.
Next check for an inoperative EGR system (if equipped)
as well as proper function of the Knock Sensor (if equipped).
Also, you will want to make sure you are using the correct
heat range plug. |
|
|
| Overheated |
 In
this instance you will notice a chalky appearance, white
insulator, rapid electrode wear as well as an absence
of deposits. The actual shell may also be discolored.
To cure this you must first verify that the plug is
the correct heat range, the ignition timing settings
are correct, the air/fuel mixture is not too lean, there
are no vacuum leaks and that the EGR valve (if equipped)
is functioning properly. |
|
|
|
Ash Deposits
|
 These
are light-brownish deposits that are encrusted to the
ground and/or center electrode(s). Oil and/or fuel additives
cause this situation. This condition can cause misfires.
The cure for this is to verify worn valve guides or
valve seals, not using fuel additives, or you might
even try changing fuel brands. By the way, a hotter
plug is what most people try to fix this problem. You
need to first understand that the plug is NOT typically
the problem. |
|
|
| Oil Fouled |
 Oily
coating caused by poor oil control. Oil is leaking past
worn valve guides, piston rings, or on some race engines
a possible intake gasket leak and then entering the
combustion chamber. Check for worn valve guides, intake
gasket sealing alignment, as well as worn cylinder walls
and piston rings. A leak down test is a good place to
start for what is causing this. |
|
|
| Initial Pre-ignition |
 This
will usually look as a melted center electrode and/or
ground electrode. Check for incorrect heat range plug,
over-advanced timing, lean fuel mixtures, inoperative
EGR valve or Knock Sensor (if equipped) and also look
for hot spots or deposit accumulation inside the combustion
chamber. If you or your engine builder took the time,
all areas of combustion chamber should have been de-burred
to eliminate this problem. This includes the sharp edges
on the chamber, piston top, and cylinder wall valve
relieves (if applicable). |
|
|
| Sustained Pre-ignition |
 This
will be pretty obvious ... melted and/or missing center
and/or ground electrodes as well as a destroyed insulator.
Check for incorrect heat range plug, over-advanced timing,
lean fuel mixtures, inoperative EGR valve or Knock Sensor
(if equipped) and also look for hot spots or deposit
accumulation inside the combustion chamber. If you or
your engine builder took the time, all areas of combustion
chamber should have been de-burred to eliminate this
problem. This includes the sharp edges on the chamber,
piston top, and cylinder wall valve relief's (if applicable).After
you see this, you'd better look for possible internal
engine damage as well. (Pistons, cylinder walls, valves,
rings, etc.) |
|
|
| Splashed Deposits |
 These
look as if they are small islands of contaminants on
the insulator. This is usually from dirty carburetor
bores or air intake as well as the possibility of a
dirty or faulty injector. Using the Fitch Fuel Catalyst
may remove these or you may want to use an aggressive
carb and choke cleaner or other fuel injector cleaner
on fuel injected vehicles or injector removal and cleaning
before installing new spark plugs and a Fitch Fuel Catalyst. |
|
|
| Carbon Fouled |
 This
is very common visual condition on race engines. Soft,
black, sooty, dry-looking carbon. This indicates a rich
mixture, weak ignition or wrong heat range plug (too
cold). You will first need to verify plug heat range.
On carbureted engines, check choke as well as choke
pull-off (if equipped) for proper function and adjustment.
On fuel-injected engines, check for clogged injectors
and the cold-start valve and circuit. You also need
to check for correct fuel pressure settings. |
|
|
| On computer-controlled engines, all input signals
to the computer need to be working and accurate. This
includes, but is not limited to, O2 sensors, all temperature
and pressure sensors, as well as the EFI system components.
On all engines, check for vacuum leaks, poor TPS
voltage and weak spark, or low voltage output. |
| |
