1985 Mustang GT 5 Speed VECI

[CoastieLT]

I have been trying to better understand and follow the VECI. I decided to make a version in Visio that would allow me to colorize it and make some notes. I think I have faithfully copied all of the diagram, but some things are still unclear to me. What are the four VCS (2 at top left and 2 middle right) connected to? Also, I think the colors are helpful in following the lines, but any suggestions to make them more accurate would be welcome.

This specific VECI is for calibration 5-21A-R01 and I believe is applicable to 1985 Mustang GT's with a 5 speed (not California).

[qikgts]

I have high altitude calibration car and don't know what the calibration number is off the top of my head. I also can't look at/check my car but I think the 2 that are on ported vacuum go to the upshift indicator and possibly the air divider solenoid. The other 2 on straight vacuum, I believe trigger the (high) altitude air bleed solenoids.

Hope that helps.

EDIT: FWIW, I just verified that my car shares the calibration number you posted.

[CoastieLT]

Thanks, that does help. It is interesting that in the 1985 Car & Truck Engine/Emissions Facts Summary Book, there are seven different VECI's for carburetor 5.0 Liter cars, but four of them are like the VECI I posted above and seem to show the High Altitude air bleed solenoids (red lines lower right), and three of them are listed as California and do not have the High Altitude or the two VCS in the upper left. I think the California one shown below is more representative of what is found in the majority of 1985 5-speed cars.

There is very little information I can find in the service manuals or online about the VCS. They seem to be a Temperature Vacuum Switch (TVS) basic part no. 9A995 and come in four colors that correspond to opening temperature (White, Brown, Red or Purple). In the Ford 1986 Understanding Emission Controls Publication it says that the TVS look identical to the Cold Weather Modulator (CWM) for the air cleaner, that they sense inlet air temperature, and are on/off control only.

Does anyone have closeup pictures of there stock TVS (VCS) switches mounted behind the driver side strut tower? How are they mounted?

From my research, it looks like one of the TVS should be purple and is connected to the Thermactor Air Diverter (TAD) solenoid. Is one side connected to manifold vacuum and the other to the TAD solenoid? If so, why isn't that shown on the VECI? Thanks for any help, I am sure there are very few cars out there that have all of these lines as originally installed.

[gr79]

[CoastieLT]

Thanks. I have that manual.

What I need to know is how the TVS is mounted in the car, and what is it connected to? What is the vacuum source and what is the other side connected to? Why does the VECI not have them connected to anything?

[CoastieLT]

Did a little more digging into old posts. I don't think the items labeled VCS on the VECI are Temperature Vacuum Switches (TVS part 9A995) after all. The TVS described previously only have an in and out for vacuum.

The VCS in the diagram must have an electrical connection that signals the TAD solenoid to open/close. Does anyone know what these look like or have a picture or part number? It seems to be called the Manifold Vacuum Switch and provides a ground (via circuit 200) according to the EVTM.

I know the TAB solenoid is controlled by the TSAD module in the passenger kick panel. (Drawn in the second diagram I posted).

I don't have any of these parts on the 85 I am working on and I am trying to determine what, if anything, should be put back on.

[qikgts]

http://vb.foureyedpride.com/attachme...4&d=1484966325



Look behind the DS shock tower.

[Bentley]

http://vb.foureyedpride.com/attachme...4&d=1484966325



Look behind the DS shock tower.

My 83 was bolted to the backside of the drivers side shock tower.......... It actuates a relay under the dash, right side of the column. Its a WOT solenoid for the smog ( TAD/TAB) system.....
I can't attach any pics to this site ( probably because of my computer illiteracy) or I would attach a pic and a diagram from my " Vacuum and Electrical troublshooting" manual.....

[85GTGuy]

Does anyone know what these look like or have a picture or part number?

Unmolested/original. Backside of driver's side strut tower.

[CoastieLT]

85GTGuy, thank you very much for the great pictures. I feel like I have a good understanding of what these vacuum switches look like and do finally.

One more question, one of them I would definitely say is purple, would you call the other one white or gray?

[85GTGuy]

No problem. I'll have to clean it off to get a better idea of the color of the "not-purple" one. Give me a day or 2 to get to the car (it's garaged elsewhere) and I'll let you know.

[85GTGuy]

And thank you very much for the enhanced vacuum routing diagrams. I'm sure they will be referenced by me in the future.

And the vacuum restrictor color code legend is really great. I hadn't seen that info elsewhere.

[85GTGuy]

One more question, one of them I would definitely say is purple, would you call the other one white or gray?

Gray.

[CoastieLT]

Great, thank you for the confirmation. Here is the final VECI drawing with notes. I hope it is helpful, if you want a clearer version for future reference just send me a PM and I can send you a PDF that is clearer or the original Visio file if you want to make some changes.

[KevinVarnes]

This doesn't apply to any of my cars, but I can certainly appreciate the time and effort required to not only research this, but also put it together and make it look good. Very nice work.

[85GTGuy]

If you have any more questions or need any pics on this stuff, ask away. I'll try to provide answers where I can.

Again, thanks for a job well done sir.

[85GTGuy]

CoastieLT, you may be interested in post #'s 2, 4, 5 and 10 in this thread....
http://vb.foureyedpride.com/showthre...ht=spark+plugs

And post #'s 2, 3 and 4 in this thread....
http://vb.foureyedpride.com/showthre...nister-missing

If you haven't already seen them.