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14 JSW CJAA Timing belt tentioner adjustment?

1040 Views 10 Replies 3 Participants Last post by  MSP1160
Good afternoon,

I just replaced a hpfp trying to eliminate some intermittent fuel issues and I decided to do the timing belt as well as all the common 110k+- things while I was there. My problem is I have conducted the procedure with the new tentioner 5 times now and I get the same result. Tighten the tentioner, rotate the engine 2x to check timing and the tab has gone from the middle/right of the window to almost 10mm to the left of the window. Not sure what the problem is but everything is new and otherwise working fine. I have done this job 4 times before and I have all required tools. Any insight or ideas? I've searched high and now for an answer I'm happy with but no luck so far. Thanks!
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Once the tensioner is set to the correct spot in the window you’re done. That is saying, the specified tightness (tension) of the belt, itselfhas been achieved.
You are experiencing the tensioner doing its job. Keeping the belt under constant, equal, tension throughout the rotation of the entire belt and keeping the teeth of the belt in contact with the teeth on the pulleys.
What you’re seeing in the tensioner window is the stretch of the belt in different locations on the belt. Say minor imperfections. As you rotate the engine, that needle is going to move as the the belt passed around the tensioner. The same effect happens with accessory belt, minus the teeth. Mark that accessory tensioner and rotate the engine and your tensioner is going to move a bit, as it should.
Piece of mind? The tensioner pulley may be defective, like off center. Possible but not likely.

Proof in the pudding?
Put the old timing belt on, with the new tensioner. And rotate the engine by hand… the pointer should move a lot more compensating for the worn timing belt.
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You are chasing your tail. You can’t slide the belt a half a tooth to get the pins to line up. Those pins are to ensure the crankshaft and the camshaft don’t move while you remove and instal the belt. The tensioner is the adjustment of the belt. Those pins are not going to line up exactly with an aramid fiber belt and a tensioner in the system. Although, a new timing chain or new timing gears would. That’s what a tensioner does, takes up any slack in the belt with a pre-determined tension setting to keep the timing aligned relative of the crankshaft and camshaft.
Don’t forget to set your torsion value via VCDS.
It takes two revolutions of the crankshaft to make one revolution on the camshaft. Why would the pins line up if you have turned the camshaft half way?
Never mind. Wish you luck!
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