1999 jeep grand cherokee limited fuel tank leaking areas

During combustion, fuel with MMT causes the entire tip of the spark plug to be coated with a rust colored deposit.

Some fuel refiners in several areas of the United States have introduced a manganese additive (MMT) for unleaded fuel. Because of coil design, spark plug cables (secondary cables) are not used. This provides heat and vibration resistance that allows the ignition coil to be mounted on the engine. The windings are embedded in an epoxy compound. This is done to meet changing engine operating conditions. Battery voltage is supplied to the 8 ignition coils from the ASD relay. Each coil is mounted directly to the top of each spark plug. The 4.7L V–8 engine uses 8 dedicated, and individually fired coil for each spark plug. To prevent possible pre-ignition and/or mechanical engine damage, the correct type/heat range/number spark plug must be used. Because of the use of an aluminum cylinder head on the 4.7L engine, spark plug torque is very critical. 4.7L V-8 engines are equipped with “fired in suppressor seal” type spark plugs using a copper core ground electrode. Did we mis anything? Please get in touch with us and tell us about it! General informationīoth the 4.0L 6–cylinder and the 4.7L V-8 engine use resistor type spark plugs.

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1999 jeep grand cherokee limited fuel tank leaking areas