Pics of my TB not opening 'fully' (big pictures ahead)
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From: chillicothe, OH
Pics of my TB not opening 'fully' (big pictures ahead)
does this look normal? notice how the bottom butterfly is completly horizontal where as the top two have a slant on them.
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Joined: Apr 2001
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From: Dublin, VA
it is probably "normal" for a car of our age and wear but it is not correct. The top plates need to be full open when the bottom plate is full open or you will not get max HP. The Haynes and FSM (if I remember right) both give instructions on how to set start opening of the secondary plates (top) relative to the primary (lower). I expect you will find as I did the primary plate has to move WAY too far before the secondaries begin to move. Most likely due to wear in the linkage.
The repair manuals say to bend the tab. I found that very difficult to do with everything installed. I removed the nut from the end of the secondary plates (upper left on your picture) and pulled the remove the plate with the tab, bend the tab and slip it back on.
If I remember right the correct opening distance was about the same as the cold idle setting. What I did was make sure the primary throttle plate was on the cold idle roller then adjusted the secondary plates until the were barely off the tab when still on the cold idle. Seemed to work out about right and at full open they were both full open
The repair manuals say to bend the tab. I found that very difficult to do with everything installed. I removed the nut from the end of the secondary plates (upper left on your picture) and pulled the remove the plate with the tab, bend the tab and slip it back on.
If I remember right the correct opening distance was about the same as the cold idle setting. What I did was make sure the primary throttle plate was on the cold idle roller then adjusted the secondary plates until the were barely off the tab when still on the cold idle. Seemed to work out about right and at full open they were both full open
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Joined: Apr 2001
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From: Dublin, VA
The FSM shows there sould be .016-.020 inches of clearance between the Primary plate and the wall of the throttle body when on the cold Idle cam and .020-.030 inches of clearance when the secondary plates start to open.
Make sure the cold idle cam is engaging the primary throttle plate and see how much farther you have to move it before the secondary plates start to open. It should barely (if at all) before the secondary plates start to move.
Make sure the cold idle cam is engaging the primary throttle plate and see how much farther you have to move it before the secondary plates start to open. It should barely (if at all) before the secondary plates start to move.
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