Misfire

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Misfire

Steady Misfire

In the case of a steady misfire, isolating the misfiring cylinder is the first step in diagnosing the problem.


Items that can cause a misfire:

Loose/disconnected HT Leads

Check they are all attached properly! (Cured my misfire anyway....)

Moisture in Distributor (Dizzy) Cap

Unscrew, check for moisture, dry off.

Spark Plugs

Spark plugs

Coil Packs

Coil packs

Throttle Position Sensor

Throttle Position Sensor

Lambda Sensor

Lambda sensor

Head Gasket Failure

A spark plug that shows heavy whitish to brown deposits may indicate a coolant leak either past the head gasket or through a crack in the combustion chamber. This type of problem will only get worse and may soon lead to even greater problems if the leak isn't fixed. Coolant makes a lousy lubricant and can cause ring, cylinder and bearing damage if it gets into a cylinder or the crankcase.

Head gasket failure

Inlet Manifold Gasket Failure

The Inlet manifold gasket can fail and allow air leaks and coolant/anti-freeze to leak into the cylinder ahead of the injectors. Tell tale signs can include rusty spark plugs on cylinder 1 and 4, sometimes even all four, lumpy idle or misfiring, high emissions, jerky acceleration and deceleration when coming off the accelerator, anti-freeze around the inlet manifold, unburnt fuel and possibly destroyed catalytic convertor.

Inlet manifold gasket failure

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