Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks
Sponsored by:
Sponsored by:

Vacuum Advance

Thread Tools
 
Search this Thread
 
  #1  
Old 11-04-2016, 08:23 PM
GeneGregory's Avatar
GeneGregory
GeneGregory is offline
Mountain Pass
Thread Starter
Join Date: Apr 2015
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Vacuum Advance

If you have a 1987 Ford F250 /350 with a 460 v8 could you please look and see where your vacuum hose goes to , from the vacuum diaphragm, on the distributor to where???
Thanks for looking , Gene
 
  #2  
Old 11-09-2016, 04:10 PM
BruteFord's Avatar
BruteFord
BruteFord is offline
Postmaster
Join Date: Mar 2013
Location: Over There
Posts: 3,066
Likes: 0
Received 6 Likes on 6 Posts
Where it went stock, or where it is now?
 
  #3  
Old 11-09-2016, 05:46 PM
ArdWrknTrk's Avatar
ArdWrknTrk
ArdWrknTrk is offline
pedant

Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 23,576
Received 15 Likes on 15 Posts
It goes to the thermal vacuum control valve on top of the thermostat housing (water neck)
'87 49 State vacuum diagram for 460.
​​​​​​​
​​​​​​​
 
  #4  
Old 11-09-2016, 05:51 PM
GeneGregory's Avatar
GeneGregory
GeneGregory is offline
Mountain Pass
Thread Starter
Join Date: Apr 2015
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Where it is now goes from vacuum diaphram to the bottom of 3 ports on the water neck , then out of the top 2 to a Y then to manifold vacuum.
 
  #5  
Old 11-09-2016, 06:02 PM
BruteFord's Avatar
BruteFord
BruteFord is offline
Postmaster
Join Date: Mar 2013
Location: Over There
Posts: 3,066
Likes: 0
Received 6 Likes on 6 Posts
If only used for the distributor then remove the temp switch from the path.
 
  #6  
Old 11-09-2016, 06:13 PM
ArdWrknTrk's Avatar
ArdWrknTrk
ArdWrknTrk is offline
pedant

Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 23,576
Received 15 Likes on 15 Posts
Originally Posted by GeneGregory
Where it is now goes from vacuum diaphram to the bottom of 3 ports on the water neck , then out of the top 2 to a Y then to manifold vacuum.
Should be going to the center port of the valve...

I edited in a screenshot.
​​​​​​​I don't have it on my phone.
 
  #7  
Old 11-09-2016, 06:14 PM
BruteFord's Avatar
BruteFord
BruteFord is offline
Postmaster
Join Date: Mar 2013
Location: Over There
Posts: 3,066
Likes: 0
Received 6 Likes on 6 Posts
Originally Posted by ArdWrknTrk
Should be going to the center port of the valve...

I edited in a screenshot.
​​​​​​​I don't have it on my phone.
Why keep the valve at all?
Edit.. NVM he's in Commiefornia
 
  #8  
Old 11-10-2016, 04:33 AM
ArdWrknTrk's Avatar
ArdWrknTrk
ArdWrknTrk is offline
pedant

Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 23,576
Received 15 Likes on 15 Posts
The valve steps up the idle speed when the coolant sensor reacts to overheating.
(fan turns faster and pump cycles more coolant through the engine)
 
  #9  
Old 11-10-2016, 11:46 AM
BruteFord's Avatar
BruteFord
BruteFord is offline
Postmaster
Join Date: Mar 2013
Location: Over There
Posts: 3,066
Likes: 0
Received 6 Likes on 6 Posts
Originally Posted by ArdWrknTrk
The valve steps up the idle speed when the coolant sensor reacts to overheating.
(fan turns faster and pump cycles more coolant through the engine)

I thought the temp valve was to turn the EGR off until the engine warmed up, but now I see in that diagram/remember that there are two. I don't care one bit about being stock or the EGR, but that sounds like a worth while feature to have.

You have any idea what temp the valve trips and how I can tell which is what, IIRC they are colored different?

EDIT...
Wait, now I'm confused, I'd never set it up like stock, but I could see using that valve to perform that function. However I'm confused about how it's set up stock. What does it have to do with vacuum advance?
 
  #10  
Old 11-10-2016, 12:54 PM
ArdWrknTrk's Avatar
ArdWrknTrk
ArdWrknTrk is offline
pedant

Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 23,576
Received 15 Likes on 15 Posts
The valve switches between the two sources. (one with a vacuum restriction (VREST) and full manifold vacuum, which pulls in more timing, increasing the idle speed.
the valves have different colors, that I think denotes the temperature.
 
  #11  
Old 11-10-2016, 12:57 PM
BruteFord's Avatar
BruteFord
BruteFord is offline
Postmaster
Join Date: Mar 2013
Location: Over There
Posts: 3,066
Likes: 0
Received 6 Likes on 6 Posts
Originally Posted by ArdWrknTrk
The valve switches between the two sources. (one with a vacuum restriction (VREST) and full manifold vacuum, which pulls in more timing, increasing the idle speed.
the valves have different colors, that I think denotes the temperature.
Well that's a really silly way to do it, so it doesn't open the throttle at all only gives proper timing, timing it should have all the time anyway. I take it back, not silly, moronic.


Ford engineer "Let's detune this engine through a complicated mess of superfluous vacuum lines, fittings and valves. That way it will be more likely to fail, get worse mileage, have less power, and overheat. That is until it actually overheats, then we'll give it proper timing, can't be replacing whole engines on warranty."
 
  #12  
Old 11-10-2016, 05:25 PM
GeneGregory's Avatar
GeneGregory
GeneGregory is offline
Mountain Pass
Thread Starter
Join Date: Apr 2015
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
I checked this gray 2 port switch in my t-stat housing for the EGR, it is closed cold and opens to let vacuum through at 150 degrees , that works I guess.
Thermostat stuck while testing so I changed it again and used a Fel-Pro black and orange gasket #35041T cause I used the funky paper gasket when I changed the Tstat last week and it weeped a little, well the fel pro gasket leaked as soon as I started it. I've had enough for today I'm beat. Tomorrow I'll deal with my water leak and try moving the vacuum advance hose to the middle port.
Thanks for all your help guys , Gene
 
  #13  
Old 11-10-2016, 06:16 PM
ArdWrknTrk's Avatar
ArdWrknTrk
ArdWrknTrk is offline
pedant

Join Date: Jan 2008
Location: EXTREME southwest CT
Posts: 23,576
Received 15 Likes on 15 Posts
Sometimes the thermostat housing has been overtightened and the ears become warped.

If you have a piece of wetordry sandpaper you can try lapping it flat using water to suction the paper to something flat like a counter top or plate glass.
Always work it in a figure eight motion.

This might solve your coolant leak.
 
  #14  
Old 11-10-2016, 08:29 PM
GeneGregory's Avatar
GeneGregory
GeneGregory is offline
Mountain Pass
Thread Starter
Join Date: Apr 2015
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
I painted it with lay out die and tomorrow I will sand it on a glass flat surface to see if its warped. Have to find a good gasket.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mmmmoore24
1973 - 1979 F-100 & Larger F-Series Trucks
6
06-25-2014 02:57 PM
williamwilliam
1967 - 1972 F-100 & Larger F-Series Trucks
12
04-13-2012 08:46 PM
Gary G
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
2
03-10-2004 11:14 AM



Quick Reply: Vacuum Advance



All times are GMT -5. The time now is 12:55 AM.