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FMX valve body info.


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Thanks for sharing! 

That is GREAT info. I've rebuilt mine (don't think I would want to do it again). 

Rod

Edited by machattack
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That's a really good source for everyone who's planning to service his FMX by himself. 

Thank you very much for sharing. 

Frank

1972 Mach 1, 351C-2V, wimbledon white, blue all vinyl luxury

born in Dearborn, grown in the district of San José, spent a lifetime in California, moved to Germany in 2010

Mustang_Mach1_wallpaper_300_150.jpg proud member of clublogozusammen.JPG.59fb4a10d15cfff9ec756235059135b8.JPG

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Is there a list in the book that gives the dimensions of each spring, i.e. length, diameter, wire gauge and spring rate?

If so, I would be pleased if you could also copy and display this list.

Frank

1972 Mach 1, 351C-2V, wimbledon white, blue all vinyl luxury

born in Dearborn, grown in the district of San José, spent a lifetime in California, moved to Germany in 2010

Mustang_Mach1_wallpaper_300_150.jpg proud member of clublogozusammen.JPG.59fb4a10d15cfff9ec756235059135b8.JPG

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Today I swapped my vacuum modulator / throttle control valve.  

Learned some things along the way.

1) Color (blue / green / etc) is a general indicator of how the vacuum servo will function, there still seems to be a lot of variability between manufactures.

2) A more radical camshaft / lower engine vacuum works better with a green vacuum modulator / throttle control valve.

3) The adjustment (in the adjustable ones) moves the stationary spring inside.  It does not change the input to the throttle valve during WOT.  All the adjustment does is alter the point where the servo starts to move.  IE- If you took a green servo (vacuum modulator / throttle control valve) out of the box that started to move at 6" and was all in by 15" you could turn the adjuster in clockwise by a couple turns and alter it to start to move at 6" and be all in by 17"...                             

4) The green servos start to move at 6-7" of vacuum, and are all in by 15-16" vacuum.

5) The blue servos start to move around 10-11" of vacuum and are all in by 19-21" vacuum.

6) The distance from tip of the pin that interfaces with the throttle valve in the transmission to the face of the vacuum modulator/ throttle control valve seems to vary a bit.  All the ones I had had the pin pocket in the movable diaphragm about .445" deeper than the machined face of the 3/4" hex where it seals up against the transmission case with a small round gasket.  There was one exception where the distance was about .100" less, and I was too chicken to run it as It shifts plenty hard at WOT.  This distance will alter how it interfaces with the throttle valve under WOT when there is very little engine vacuum.  There is no adjustment for this, other than making a longer or shorter pin, or possibly using thicker gasket / copper washer.

 

With my blue servo low engine vacuum it was running around with higher pressures most of the time.  That resulted in me feeling downshifts as I was rolling to a stop.  With a green servo that all went away and it feels perfect.  Nice light low throttle shifts, not discernable jerk as it is slowing to a stop but still rock hard shifts when I have the pedal flat to the floor.  Feels pretty frisky now.  Anyway if you have lower vacuum at idle (10" ish I highly suggest a green)

 

 

A9321FC1-AB05-41D3-878F-D9F849606E58.jpeg

Edited by Bentworker
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