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Valve Springs?

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Morris

Morris

Yoda
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I have a bouncing vacuum needle through out the range on my car. I have explored every possible cause extensively, and I am still stumped as to what is causing the problem. When I had the head rebuilt, I had the machinist shave off .05" (if I remember correctly). I bought new valve springs, but they are stock spec. Could it be that stock springs are not strong enough to seal my combustion chamber given the mods I have made?
 
Mo.......

Easiest is to tape over the vacuum gage and fogetaboutit.

Engine run crappy to match rate of bounce ...or not. IF you have a new vac gage and you tapped into one cylinder and not the plenum of the intake manifold you will have this condition on the gage.

Seriously tho.......it sounds like a realy weak valve spring (like a broken one if you have inner and outer springs). First thing I'd do is valve cover off and check the valve lash and poke around all the springs and use a strong flashlite.
 
What is the position of the tap for the vacuum relative to the intake runners off the plenum?

Glen
 
It's between the throttle body and the plenum.

Had a long chat with the machinist who built the head. He thinks that I still have a hidden vacuum leak.

I hurt my back, but as soon as it gets better, I will pull the manifold and see if it gives up any secrets.
 
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