My transmission is not shifting like it should.It won't shift into second until 30 mph and third until 50 mph.I've checked the vacuum at the manifold on the firewall and it slams the guage to 25 inHg but if I put the guage on the line to the doodad (don't know what it's called) on the side of the IP it slowly rises to 25 inHg.The line that leaves the doodad going to the modulator valve has no vacuum on it.Also, my modulator valve is the one with the purple band. Is there a difference in the purple and green modulators.

 

Vacuum regulating valve.......

How to adjust VRV by James

You don't have the engine running for the test, you need to apply 20" vacuum (Hg) to upper VRV port and attach vacuum gauge to lower VRV port. The lower port is the one that goes to tranny, the upper to vacuum pump.
You have to maintain 20" vacuum (Hg) througout this test. If it drops off you need to pump it back up.
Remove throttle return spring, cycle throttle lever 5 times from idle to WOT. Make sure 20" vacuum is maintained on upper port side.
Move throttle so it is 0.515" (33/64") from wide open (they make a tool for this). Vacuum gauge should read from 6-8" of vacuum (Hg). If incorrect adjust VRV to 7".
Again apply 20" vacuum, cycle throttle from idle to WOT 5 times. Return to idle. Gauge should read at least 13".

It says if you can't get the 7" or the 13" to replace the VRV. If VRV checks out maybe the diaphragm (modulator), line from VRV goes to the vacuum diaphragm I believe. Can't find any adjustment for the diaphragm but I think there is a little.

Basically all you need for the test is a vacuum pump (handheld type), vacuum gauge and a ruler to measure 1/2" or a 33/64" drill bit in lieu of the .515" tool. And a screwdriver for any adjustment needed.
Good Luck
James

Note..... 20" vacuum Hg is equal to MINUS 65 Kpa..........

 

I'll try t ocome up with the tools to do that test.The previous owner said it was replaced and it does look new.Should there always be vacuum on the outlet side or only when it is adjusted correctly? Do I need to change to the green modulator?

 

the color of the band on the modulator is a reference to elevation. if i remember correctly, purple is for sea level, green is for higher elevation, and white is for high mountain regions.
when i put the C6 in my 88 diesel, it came with a green band, and would not shift at all. i switched it to a purple band cause i am in New Jersey, and 99% of the shifting problems disappeared.

 

Could have been replaced but not set correctly.....if it is not set right then it will give false info. Just for kick try loosening the hold down bolts and rotate the VRV to the clockwise direction in small increments and test it by driving. If there is a difference to the good then do it untill your satisfied until you can reset it by the numbers.

Don't have the skinny on the modulator. sorry.

 

by the way is this truck supposed to have a vacuum cannister of some type?I can't seem to locate one anywhere.

 

No 48 oz juice tin.........

 

So you're saying that I should have a large tin can looking thing somewhere in the engine bay right?there is nothing in the vacuum system like that.

 

should be on the right hand side on the fender well...

 

you might want to make sure the vrv is installed in the proper position on the throttle lever. If its on the back side of the lever it wont work properly and you'll get eratic shifting.
check both sides of the vrv hoses to make sure one of the hoses from the main vacuum line isnt collapsed internally.
as long as the engine is running, it will make vacuum from the vacuum pump.

 

Thanks for the replies.I tried to set the VRV but I'm not sure I did it right.I don't know how to keep 20" on the VRV while you are cycling the throttle.Probably just don't uderstand what I'm supposed to be doing.There is absolutely no vacuum cannister under the hood of this truck.Do I have to have one for everything to work correctly?If so,can I get a can from the parts store(any can)and plumb it into the system?How is that done?

Thanks Greg

 

I have questions too. I have a 94 7.3 IDI Turbo with a E4OD trans. Should I have this so called VRV (Vacuum Regulated Valve) on my truck as well. I was just looking and could not find it. Does the E4OD have a vacuum line attached as well as the C6 trans.
I was reading a post about hard shifts and a bad VRV, so I searched and lead me to look under my hood and didnt really see a vacuum line running to the IP, like most of the post stated. But those post were regarding C6's. anyways thanks in advance.
One more thing. Is the VRV (Vacuum Regulated Valve) the standard terminology for FORD Parts? Is there a part number that someone knows off hand.
Thanks
Gary

 

E4OD uses wires to control the transmission, no vacuum involved.

You have an FILP sensor on your injection pump to direct the transmission.

 

Thats what I thought,

Thanks again
Gary

 

How does a VRV work. I know that the modulator valve has to have vacuum on it at all times unless ur getting on it. So if one side of the VRV has supply and one goes to the mv, even when ur getting on it its still gonna have vacuum when u open her up cause theres no where for the vacuum to go. If the VRV is completely at rest should vacuum be able to flow through it? Im working on a truck with the same problem. If i floor it it changes like ur just tooling around but when i too; around it winds up. WTF?