Still working on the vacuum connections on my truck. I've spent two weeks studying various vacuum maps as well as reading and re-reading "Chiltons 1965-86 Ford P.U." and ditto 1976-86. No map matches my system. Several configurations are possible. Best resolution seems to identify all the components and make my own map. This NON-cat truck has a) AIS, b) PCV, c)TAC, d)EGR(vacuum type with a now obs/nla, remote mounted, "EGR back pressure valve") , e) Evap, f) Single diaphram dizzy, g)Trans modulator, h)Vac choke motor, and i) Anti-stall vac dashpot. The Carb =Moto 2500 2V.

OPTION One:The most basic EGR/Dizzy contol system utilizes a single, two port, 95 degree PVS(ported vacuum switch) in the water outlet which is the teed off to both the spark port and the egr port(via a check valve). . The single diahpram dizzy is, according to one map, also teed in to this same circuit.

Another map descripes simultaneous control of the tranny modulator with egr vacuum, based on coolant temp.

Several maps show the need for additional switches to shut down AIS and EGR based on engine speed and temperature.

Can someone help identify the following ports on this Motocraft 2500 2v?
Carb has three small vac ports plus the larger PCV port. From the rad side looking foward: (1) on the center left in horizontal plane, (2) next is left rear angled up, (3)last is on the rear near the PCV port. Vacuum test shows variable vacuum at (1) at medium and high speed . (2) behaves similarly to manifold vac readings. (3) seems dead.
Which ports are spark/EGR? What is port(3) on rear for? Which should be connected to the 95 deg.PVS? What devices can or should I add to modulate the EGR? What vac sources should I use for the AIS(air injector sys.)?, the TAC(thermostatic air cleaner)?
Should I add another PVS to the spare hole in my water outlet? As mentioned above, there is just one, two port 95 degree PVS on the engine now.
Any advice would be greatly appreciated.

 

Follow-up-: I've installed the vac lines per the basic diagram (opt 1 above). This just doesn't work. As soon as the engine coolant reaches 95 deg., the EGR opens up giving a very rough idle. I believe that the EGR should not open below 2500 rpm. Can anyone confirm? Later models employed a speed sensor with a speedo cable and an electronic pick-up, but my early 77 never had it. Another system which came later is the CATS (cold activated temp sys). I don't think that would help here since the problem seems to be how to cut off vacuum to the ERG at warm idle, yet still allow it to operate when driving. Can't get my smog cert without the EGR hooked up. Possible that carb ports are not delivering proper vacuum? Still not sure which is spark port and which is EGR port. Hope someone can help.

 

The EGR usually works off of ported vacuum. Port #1
The tranny should have manifold vacuum. Port # 2

The Vacuum advance should work off of the #1 port.
Use a Tee on Port#1. Connect one side of the Tee to the vac adv. Connect the other to the 95 deg PVS and from the PVS to the EGR valve.

I would just plug off the dead port. It should run fine.

 

LXman is right. The EGR should only open above idle and disengage at WOT. On a simpler set up, a ported signal off the carb is the vacuum signal inline with the water outlet switch between the two. Now, on your setup it sounds like you've got some sort of high temp compensator too (typical on big motors). Have you determined the calibration code? I think I have a '77 book of diagrams laying around.

 

Finally found the problem. An exhaust back-pressure valve is required to control the egr on pre-78 engines. It was not shown in any diagram or manual I had seen. This valve controls vacuum to the egr by bleeding it off unless there is exhaust back pressure. It's a small disc with a tiny orifice mounted on a flared tube with a spring clip (near the egr). Release it from the tube and clean out the carbon from the valve's orifice to restore operation or replace the valve. Replacement valves are available for about $75 and come as an assembly with manifold/carb spacer and flare tube. Later engines have more elaborate egr vacuum control devices or are electrically operated. I don't know why Chiltons shows the circuit with just the 95 degree PVS as a control-that just doesn't work.