What should vacuum be?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
To really test what vacuum your engine is capable of maintaining, you need to remove the vacuum lines to all systems (including power brakes, headlights, wipers, etc.). With engine warmed up and idling, hook vacuum gauge to fitting (with other fittiing plugged off) and THEN read vacuum. At that point, you can also adjust the distributor timing to fine-tune it, if you want. That reading is your "baseline" vacuum reading. Now if you hook everything back on and measure vacuum again, you will see if you have any leaks in the vacuum system. Normal max vacuum on a stock 'base' engine should be 18-21" Hg. If you reconnect everything and get no more than 1" Hg (or so) drop in vacuum, you have a pretty tight system. Lower than that would indicate a leak path somewhere. If the system works fine, ignore the difference; if it operates poorly, find and fix the leak(s).
Safety Car
Joined: Oct 2007
Posts: 4,360
Likes: 1,724
From: Seattle Area Washington
Something for you to look at as it happened to me. When you install the air cleaner make sure that the rubber line connected to the metal line going to modulator is not pinched. My car didn’t shift correct after I replaced the intake gaskets years ago and I found that the rubber line had been pinched down by the air cleaner just enough to cutoff vacuum.
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Thread Starter
Instructor
Joined: Mar 2008
Posts: 235
Likes: 1
From: Waynesburg PA
I have a new moduator installed and I have checked the steel line. I blew it out and even installed a new line (rubber) line. Had governor cleaned. Its stumping 2 mechanic and a transmission guy as we speek.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
If it is shifting early, the governor regulator valve (in the shaft of the governor) might be stuck also. If that is the case, you will shift at the same RPM's regardless of how much throttle you give it (light or heavy).
Thread Starter
Instructor
Joined: Mar 2008
Posts: 235
Likes: 1
From: Waynesburg PA
Its not ****ing into 3rd on its own, its holding 2nd under throttle until you let off the gas, then it will shift and ride 3rd until you give it more gas or you come to a grade. Then will come back up to 2nd. (see some of my other posts recently).