The 1991 Acura Integra timing belt replacement is necessary because of the stretching of the belt rather than from wear. The timing belt has a spring-loaded tensioner that has limited travel. When the belt stretches beyond the limits of travel of the tensioner, the tensioner becomes ineffective at keeping tension on the belt. When this happens, the belt can come off. Acura has identified this engine as an interference design, which means that in the event of a belt failure, catastrophic damage would occur. To prevent this, Acura suggests replacing the belt at 90,000-mile intervals.
Raise the front of the Acura Integra, and support it on jack stands. Remove the left wheel, using the ½-inch drive breaker bar and the appropriate socket. Remove the inner splash shield, using a ¼-inch drive socket. Remove all the accessory drive belts, using a wrench.
Loosen and remove the power steering pump from the engine-support bracket, but do not remove the hoses. Just move it out of the way. Use the appropriate socket to remove the bolts. Remove the valve cover, using a 10 mm socket.
Place the floor jack under the oil pan to support the engine. Turn the crankshaft counterclockwise, using the appropriate ½-inch drive socket, until the timing mark on the crank pulley aligns with the "0" mark on the timing cover. This is top dead center on the No. 1 cylinder. Remove the crankshaft pulley bolt, using the appropriate size ½-inch drive socket and breaker bar. Remove the pulley.
Remove the upper and lower timing belt covers, using a 10 mm socket.
Check the timing marks again. The crankshaft sprocket mark should be aligned with the mark on the block at the 11 o'clock position. The camshaft sprockets have the word "Up" between the spokes with a corresponding mark directly above the "Up" mark. The line above "Up" should be exactly at the 12 o'clock position on both camshaft sprockets, and these marks should be aligned with the marks on the cylinder head, in the vertical position. There is a mark on both sprockets, at 3 o'clock on the left sprocket and at 9 o'clock on the right. Both of these marks must point toward each other. If the camshaft sprocket marks are not close, turn the crankshaft one more time and they will line up. It takes two turns of the crankshaft for one turn of the camshaft sprocket.
Loosen the bolt on the belt tensioner with a wrench, push the tensioner away from the belt and then loosely tighten the bolt to hold the tensioner in place. Remove the timing belt.
Install the lower timing belt cover temporarily, then push the crankshaft pulley on. Make any adjustment necessary to align the crankshaft pulley perfectly with the "0" mark on the cover.
Insert a 5 mm Allen vertically into each camshaft bearing cap directly behind the camshaft sprocket to align the camshaft. Move the camshaft as necessary slightly so the Allen will insert into the groove in the cap. Leave these Allens in place for now.
Remove the crank pulley and lower timing belt. Install the timing belt, starting on the left side, keeping all the tension on this side away from the tensioner. Loosen the tensioner bolt and allow the tensioner to operate.
Check the camshaft sprocket timing marks and reinstall the lower timing belt cover and crankshaft pulley, then recheck the timing marks. Install the crankshaft bolt. turn the crankshaft two turns counterclockwise and realign the timing marks. This helps the tensioner absorb all the slack in the timing belt and checks for misalignment of the timing marks. Do not attempt to turn the crankshaft if you feel resistance. This means the timing marks are not properly aligned and should be reset. If the marks are still aligned, turn the crank four more times and check the marks for the last time.
Check the timing marks, looking at them directly from the front. If you view them from the side there is a different perspective and the timing marks could be off a tooth. One tooth off can be catastrophic. Install the remaining parts in reverse order of removal. Torque the crankshaft pulley bolt to 180 foot-lbs. of torque.
