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Timing Belt running off of pulleys
Topic Started: May 7 2011, 06:44 PM (2,092 Views)
phwsteven
New Member
[ *  * ]
Hello,

I am having a problem. Setout to change my base cam shaft with an XFI cam.

1) The first thing is that the cam pulley difers from the model years. So, I used my base cam shaft gear on the XFI cam and installed.
2) Using the same belt because it only had 3000 miles on it, I decided to run it without the cover and the belt walked about half way off.
3) After playing with tension and taking everything apart and examing it, reassembly, same problem. In the short times I've had it running it seems really good, but the damn belt continues to back itself off.

Has anyone ever seen this before, and how do i fix it?? :banghead



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iamgeo
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Big League

Were you just making a test run without the crank pulley installed? If so that is why the belt walked off. I did the same thing.
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iamgeo
May 7 2011, 06:52 PM
Were you just making a test run without the crank pulley installed? If so that is why the belt walked off. I did the same thing.
:gp

There is absolutely no way the timing belt will walk more than to the edge of the camshaft gear, a long as everything is properly installed. I have run a few miles without the timing cover to check for seal leaks prior to reinstallation.
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chubart
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I don't have a cover and mines perfecto...that really doesn't help our friend with his question though. However I would agree, if everything is lined up it shouldn't do this, obviously, how's the tensioner is that bolted in and tight?
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Memphis metro


Is the bolt in the timing belt idler tight?
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phwsteven
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thanks for the quick replay guys and yes I am running the engine without the crank pulley.
I never thought that would make a difference because the edge of belt would have rub to stay
in place. please more info.
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chubart
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Well that's about it. Put it all back and you should have a good one.
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Deleted User
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phwsteven
May 7 2011, 07:17 PM
thanks for the quick replay guys and yes I am running the engine without the crank pulley.
I never thought that would make a difference because the edge of belt would have rub to stay
in place. please more info.
:'( Guilty, as charged! :D

You can't hide from the psychic powers that lie within the Geo Metro Forum. Use the force!

Also, don't forget the large washer between the crankshaft gear and the oil pump. :coffee

Got a camera? How about some pictures?
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phwsteven
New Member
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OK men I have done this on 2 other metros and I always use the FORCE!
this is an easy check to make after cracking seals as for the tensioner its new
and was adjusted maney times to no effect. as for now it time to switch from
wrench to highball glass.
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chubart
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Nicely put. Enjoy :beer
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mcmancuso
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The timing belt will walk off without the big belt pulley on there to hold it on, just the way it is...
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phwsteven
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Ok the final word is if you look at backside of the crank pulley it is clear that the belt runs against it as a guide.
So out for a drive I went, the first thing I notice Idle seems smoother and this change to the XFI cam more power
at lower rpms. hope this nets an MPG improvment. I have no clue what the timing should be as for now there is no
knocks or pings.
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Deleted User
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Nice! :thumb Did you install a modified camshaft gear to advance the timing? 10 degree base timing ignition seems to work well.
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starscream5000
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Got 70 MPG?

Start at 8 (nice and safe) and work your way up until you start hearing a high pitched metallic rattle at engine load in fifth gear, then back timing off until it dissapears.
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