4.0L tune-up

[catfish]

The engine fan load does not kill water pumps.
Belt tension kills bearings.
So make sure you have your belt only as tight as needed to not slip on the A/C and alternator.

 

[bldeagle10]

What was the part number for the Bosch Injectors?

http://precisionautoinjectors.com/product.sc?productId=32&categoryId=3
those are for 99+ 4.0 they have other jeep ones as well...

The engine fan load does not kill water pumps.
Belt tension kills bearings.
So make sure you have your belt only as tight as needed to not slip on the A/C and alternator.

that was just something i had heard while reading a write up on replacing the mechanical fan. weather it is true or not...idk your input sounds more legitimate. i should still get a minimal increase in mpg and power.

 

[Jim K in PA]

The stock 4.0 mechanical fan has a thermostatic clutch, so it puts a negligible load on the engine unless you are moving slowly off-road or in traffic. The stock fan pulls more air than most electric aftermarket fans. An appropriate electric fan pulls a lot of amps, and therefore puts a lot more load on the alternator and engine at low speeds. No free rides . . . You will see no improvement in mpg or power if you replace a properly functioning clutch fan with an electric.