83QV no fast idle when cold and hard warm start

What is the ambient temp when you say "cold"? 1980-1983 3.0L US models are the most likely to have been modified in some way (because of the cold start air valve), but the AAV should still be present, and should provide some small idle increase if the cold start-up ambient temp is say ~65 deg F, but, at ~80 deg F, it won't do much at all (except overcome the friction of cold oil). About all you can do is have a peek inside the AAV and see if it is open much at what is "cold", see if it opens more when placed in the frig, and confirm it closes when placed in the oven.

For the warm restart problem = Yes, measure the fuel pressure after warm-shutoff to see if that's the issue, but one preliminary thing that you can do (if US version) is remove the fuel return line from the back end of the Accumulator (or at the fuel tank end). If fuel comes out when the engine is running = you need a new Accumulator for sure. It's more obvious on euro versions when the Accumulator fails as fuel just drops on the ground; the return line added to the US versions hides this failure.

PS Are you a professional Mechanic? Your profile says that you have no personal Ferrari?

 

Thanks, but you should add "US version" for better completeness.

No, don't know of anything CIS-related "under the engine". The item B labeled "Warm-Up compensation" in that Fig 57 of your OM is the Warm-Up Regulator.

Certainly, if the entire engine has all cooled to ~40 deg F, the AAV should be opening up and adding a fair bit of air at that temperature so do check its operation. Another possibility is that if the cold start air valve has been removed, it may have been done improperly in a way that would make the AAV ineffective.

All of that sounds like goodness. There is an o-ring inside the fuel pressure regulator section of the K-Jet fuel distributor (a.k.a. Mixture control unit in Fig 57) that also must seal well to not lose all fuel pressure at warm shutoff; however, making the fuel pressure measurement at warm shutoff will tell you if you need to go here or not (since you already seem to have a fresh Accumulator and Fuel Pump Check Valve).

Don't like that at all, nor even have a theory for what would cause that to be. Having the capability to make the fuel pressure measurement will let you check the basic things like the cold control pressure, the warm control pressure, and the regulated fuel supply pressure just to make sure these basic things are healthy.