Idle issues with a '95 3.6 in an '84

[Tremelune]

I have an '84 with a 3.6 out of a '95 993. That's a lot of numbers.

When I start the car cold, it will not idle without a bit of gas for a minute. When it's warmed up, it's fine, but does have a bit of surging/roughness. Everything behaves phenomenally off idle.

I did not do the swap myself, so I am not certain of exactly what I'm working with. I have what I believe to be a 993 Mototronic unit under my seat, an '84 DME relay next to that, and a conical air filter in place of the stock unit. I do not know what a WUR is.

...Where should I start?

[umgang]

Clean your idle control valve_ silver canister looking thing on top of the motor
it gets gummed up_ carburetor cleaner douche that baby out.

[Tremelune]

Well. Bummer.

I pulled the ICV, and the inside of it was completely black with soot. I could feel the valve move, but softly and slightly.

I put it in my ultrasonic cleaner with some Simple Green until the water stopped getting darker...It was black and nasty after about 30 minutes. I sprayed it out with brake cleaner until it was shiny silver and the valve moved with no resistance at all.

Put it back on the car with the arrow pointing from the air filter to the intake manifold, reconnected the wires...

No real change. It won't idle on startup. After a minute of throttle, it will idle smoothly at 1000rpm, though. When warm, it usually idles between 1000-1100rpm, with 50-100rpm surges in a rhythm.

[umgang]

Is it chipped?
Interestingly, i have a 1991 C4 also, with that same 3.6 L motor.
Since it got cold out it has been exhibiting similar characteristics:
on first start up, some of the time, if it does not catch and the car dies. I have to use throttle to get it started.
It tends to oscillate in RPM for a minute or so, then it gains it's composure and runs great.
And runs great all day long, every start up just fine.

This has only happened since weather change. I had no problems whatsoever through Spring- Summer -Fall last year. And as it is warming up, the car is starting more often as it should.

Jeff Gamroth @ Rothsport tricked it out really nice with a chip, RS cams, Cup car flywheel and clutch, and other proprietary goodies he is known for.
I explained to him the above and he said "don't worry about it" no harm done.

In my situation, it seems like the same action that manifests the "blip" of throttle electronically through the chip [ such as when you are coming to a traffic light]; is the same blip that either catches the idle at start up or doesn't. When it doesn't, it dies and i have to use some throttle to get it running.

Don't know if you see any commonality here but might help you out.
Nic