How many hours does it take to replace the crankshaft pulley on a 1991 mazda protege?

Presuming the timing belt has not been removed or has skipped.
If the belt is removed or skipped this is an interference engine, valves and or pistons could be damaged by turning crankshaft, seek professional help.
Turn crankshaft clockwise and align timing marks (see jpg).
Face the marks (I) and (E) of the camshaft straight up, then align the timing marks with the horizontal surface on the cylinder head.
Pulley boss position pin on the crankshaft should be facing straight up.

This is only the beginning of an involved process, 3 pages in shop manual. I recommend getting a manual, many available on line. one typical Mazda 323 Protege Repair Manual 1990 2003
insure that the manual you get has info on your engine.

there is a tensioner pulley that when you put your wrench on it and tighten it will move the pulley and give enough slack to put new belt on

Is it reverse thread?

According to my book, Protege and 323 are the same, but only 1990 and 1991 model years.

1 Locate the crankshaft pulley on your vehicle. This is usually on the driver's side, but may be on the passenger's side if your timing belt is located on the passenger's side. Place the end of the tire wrench over the lug nuts of the appropriate wheel of your vehicle and turn the wrench about 45 degrees. 2 Put your emergency brake on. Then use the floor jack to jack up the vehicle's front jack point (an extension of the frame).3 Put the jack stands under the frame of the vehicle. Then, lower the vehicle onto the jack stands. 4 Continue to loosen and remove the lug nuts, and pull the wheel off.5 Remove the plastic rivets that hold the splash guard in place in the wheel well. To do this, you need to wedge the screwdriver in between the rivets and the splash guard and pry them out.6 Locate the crankshaft pulley. It will be right behind the splash guard you just removed.7 Remove the crankshaft bolt using the crankshaft bolt remover tool. Place the tool over the crank pulley bolt in the center of the pulley. This device prevents the pulley from rotating while you loosen the bolt.8 Place the socket end of the impact wrench over the crankshaft bolt remover tool. Set the impact rench to turn counterclockwise and turn on your air compressor. Wait until the compressor is fully charged. Then, work the bolt loose. It may take a while as this bolt normally requires in excess of 800 ft lbs of torque to remove.9 Attach the arms of the crankshaft pulley removal tool over the pulley and tighten the tool to the pulley using the tool's supplied bolts. Continue to tighten the tool using the bolts until the crankshaft pulley is pulled off the crankshaft.

That seal is called the front main seal. You will need to remove the crankshaft pulley to replace it. The seal is fairly inexpensive and the repair shouldn't take very long. Make sure to inspect the surface of the pully for any wear. Some tmes the seal will wear a groove into the pulley and you will need a repair sleeve, also failry inexpensive.

The main front engine oil seal may be leaking oil onto the crankshaft pulley and serpentine belt and causing the problems you describe.

Scan PCM for codes. Check that timing is correct again.These DOHC engines are easy to install a tooth out. Start from the top of engine when installing timing belt on this type of engine it's the easiest way to do it. If you took CRANKSHAFT pulley apart make sure the pick up ring behind isn't placed in backwards.

here you go buddy

http://forums.mazdaworld.org/index.php?showtopic=25269

http://www.2carpros.com/forum/1994-mazda-protege-replacing-a-blown-head-gasket-vt206242.html

http://www.2carpros.com/forum/2000-mazda-protege--my-timing-belt-broke-again,-oil-pressure-vt253721.html

http://www.blurtit.com/q298393.html

hope this helps.

thanks,

voodoo

You've got to loosen the mounting bolt first, which is located behind the pulley itself. Rotate the pulley until the large opening allows access to the bolt, then use a socket with a narrow head to turn the bolt, just until it starts to turn freely.
Then there are two locknuts on the adjuster; one right near the mounting bolt and one underneath towards the middle of the pump. Loosen both of those, and then *finally* you'll be able to turn the adjusting bolt that faces the front end of the car on the end of the adjuster arm. It's a long bolt; just keep turning that thing until the belt loosens enough to come off the pulley.
Best of luck!