2.3L ('83-'97) High RPM @ startup

[ForgedCrank]

1994 Ranger 2.3L 5sp XLT 2WD, no modifications, 100% stock

Ok I wanted to see if you guys would weigh in here. I've been fighting this thing for a month or two, and have come up short on a resolution.
At startup, the engine instantly revs up to about 2200-2400 RPM and then settles back to about 1600. Then after about maybe 30 sec or so, the idle slowly drops to a normal 750-ish over the next couple of minutes.
Temperature (ambient) doesn't seem to make any difference, and the instant rev is making my teeth itch, especially as the weather gets colder and colder.
So far I've replaced the IAC valve (twice), and the TPS (OEM Motorcraft). When at temp, all of the tests work... unplugging the IAC, etc. Once warm the thing appears to operate somewhat normally. One new thing I also notices is that before this started, I could be driving and drop into neutral and coast, the idle would drop to 800 or so and stay there. Now, if I do the same, it will only drop to 1200-1300 until I get down to about -10mph, then it will drop to normal idle.
I've tried 2 diff IAC's, one of the cheap Amazon ones, and the one mentioned in another post that I believe is Motorcrat OEM. The one on it now is the Motorcraft one. Changing it has made no difference.
I did a smoke test on the intake and I have 3 "leaks". One is the IAC vent, and I believe that is normal and expected (please correct me if I'm wrong).
The second is a slight weeping from the EGR diaphragm housing. It has some holes punched in it around the circumference and a very small amount of smoke is escaping there. Is that normal or no? Anyway, my guess is that it's such a minor leak, it shouldn't be causing this havoc, but that's just my guess, maybe it is?
Lastly, smoke is escaping from what appear to be vents in the top of the square charcoal canister that is mounted near the radiator support... and since they are vents (I think), I assume that is expected behavior?

Anyway, this thing operated perfectly for about a year and then this started happening one day and I can't figure out how to settle it down. I'm almost afraid to start it anymore, afraid I'm gonna spin a damned bearing or something. Previous behavior was @ cold startup, it would rev to about 1200-1400, and immediately drop to 1000, then gradually go down from there.

Anyway, do you guys have any input for me? I really would appreciate any feedback.

 

[RobbieD]

It's a puzzler to me, too.

Just curious; right after you've started it and it's doing its hi-rev thing, does popping the throttle cable off the throttle body ball stud make any difference?

 

[ForgedCrank]

It's a puzzler to me, too.

Just curious; right after you've started it and it's doing its hi-rev thing, does popping the throttle cable off the throttle body ball stud make any difference?

I actually thought about that (and the cruise control). I unhooked both and it makes no difference unhooking then, either before or after startup. Also, snapping the throttle doesn't settle it either

 

[ForgedCrank]

It's a puzzler to me, too.

Just curious; right after you've started it and it's doing its hi-rev thing, does popping the throttle cable off the throttle body ball stud make any difference?

This one has me stuck. Even the hail-Mary parts cannon has failed me. It's about ti kill me thinking I might have to give up and take it to someone else to diag.
I can't STAND getting beat like this. hehe

 

[SenorNoob]

You said it has smoke at the charcoal canister? Sounds like the purge valve is stuck open. Unhook that line from the intake and put a cap on it. Then start it.

 

[ForgedCrank]

You said it has smoke at the charcoal canister? Sounds like the purge valve is stuck open. Unhook that line from the intake and put a cap on it. Then start it.

I'm going to do that here in a bit but... I can't find a purge valve on this system. I also can't find the diagram in my freekin manuals. I know it has to be in there somewhere. What I do know is that the vapor canister has a straight run to the lower intake manifold and there is no purge valve in that section, just a straight shot through a vacuum line. Is it on the gas tank or something? My searches are coming up empty do far in identifying the thing.

BTW, I appreciate the feedback.

Edit:
Ok, I plugged the intake vacuum supply @ the intake... the pipe that goes from the intake to the canister. No change in behavior. I also plugged the EGR vacuum control line just in case and tested again. no change with both of them blocked off

 

[SenorNoob]

Should look like this:

Someone might have removed it at some point...

To do any good it has to be between the charcoal canister and the intake....

 

[ForgedCrank]

Should look like this:

Someone might have removed it at some point...

I did edit my previous reply. The test yielded no favorable change, its the same with the vacuum blocked off.
Right now there is 8" of snow on the ground so I'm resistant to crawling underneath the thing right now. I'll try to pull it into the garage tonight and see if that thing is downstream somewhere underneath the truck. I do know that it doesn't exist in the engine bay and I'm 99% sure there are no stray connectors flopping around anywhere. I documented this all very well when I pulled the head off last summer.
I did see a post that mentioned that prior to '95, there was no purge valve. Could that be true? Seems a valve would almost be required, but maybe not. My EVAP vacuum source isn't pre-throttle body, it is sourced from a nipple straight into the lower intake.
I'm referencing this post, 1st reply by RonD --> [LINK]

By the way, you wouldn't happen to know where in the Ford shop manuals this is all documented would you? I can't find it to save myself.

Edit:
I studied it a little bit more just to be sure. There absolutely is no harness connector for one of these in the engine bay. I am also 100% sure nothing was nipped off in the past. I was meticulous documenting the wiring harnesses when I did the head work and I am positive that it's all intact. I have one straight tube (hard plastic maybe 1/4") straight from the lower manifold plenum from the canister under the hood. This is hard plastic and molded, fairly obvious as-built as it routes perfectly around everything on it's way to the canister. Then out of the canister a tiny line headed back under the truck. I'll do more recon when I get it in the garage and see what is underneath and where that tiny line goes next.

 

[ForgedCrank]

I found this, it shows my system exactly how it is on mine. [LINK]