Golf mk1 2liter 8valve agg carburetor motor

Hello ,I have some trouble with my car,std 2liter 8valve golf mk1 agg carburetor motor with a 276 cam,the problem im facing is when i drive and the engine is warm and i park it for 30-40 minutes and then try to start it the car takes about 7seconds of cranking before it starts but if i leave it for an hour it start perfectly in one kick, same if the engine is warm and i switch it off and restart the engine it starts perfectly ,something is happening in that 30-40 minutes when i leave it,it is a freshly build motor and it did that before the rebuild aswell,other than that the car drive perfectly ,hopefully someone had this problem before because I'm wasting money on parts that isn't the issue .

Things i have changed:
New carburetor+baseplate
New distribitor with leads
New fuel pump
New coil
New tp-100 module
New fuel tank breather
New fuel separator,does the same without and return line blanked off
New steel fuel filter
The choke is wired fully open all the time

I just have some basic questions as I am on the other side of the pond, and well I have seen similar issues with Carbs over the years.
Vapor Locked.

Do you have a mechanical fuel pump or a Electric?

If electrical, do you wait 4 seconds from key in run  prior to engaging the starter for it to re-pressurize the fuel lines, and fill the bowls of the carb?

If Mechanical then I would be concerned that the fuel lines be insulated from the engine heat as over here with the advent of E-rated gas, in the early 80's the routing of the fuel lines caused the fuel to evaporate or become Gaseous in the lines causing the fuel to be vaporous after run or vapor locked.  Had this issue on 2 cars mid 80's where the fix was to use insulate heat wrap on the fuel lines where they wormed around and over the engine.  Once insulated they stopped the intermittent fuel starvation issue on start after run.

The same thing can happen to fuel lines on a electric pump.

Do you have all your radiator cards specifically the upper radiator card installed?

The upper radiator card prevent the fan from recycling engine compartment air back over the radiator making it effectively hotter, which can cause
the Carbs to vapor lock.

Here is a thread on Cold air intakes, and under the hood temp measurements
https://www.vwvortex.com/threads/debunking-the-cold-air-intake-myth.2514928/?id=2514928

Have you verified that your ground cables are in good condition?

Electrics, in the VW's are notorious for the major grounds to get "iffy".

They used un-shielded multi-stranded Cables from the Battery to the Frame and the frame to your engine/tranny.
Over the years this can cause corrosion between the strands of the cable and insulating them reducing the main cables ability to carry current.
On a 20 year old minimum cables it is a great idea to check them for Voltage Drop, and or cleanliness.

Salt spray on the roads over the winter, and road spray off the highways can cause corrosion to start and blossom.
If you see dingy oil fouled cables it might behoove you to remove your grounds and soak them in vinegar, or a battery corrosion remover, then clean your bolts and
connections on the frame.

One a new to me car, unless brand new, I usually replace all the major battery cables with new ones off the shelf shielded, then take steps after cleaning all the ground connections with battery corrosion paint to seal them.

I had a car that on 50 degree rainy days would not start occasionally.  I rebuilt the Distributor, new wires and plugs, but it still would continue.  I replaced battery terminal ends
as the ends looked shiny and clean, I never inspected the cables.  One particular wet day under the hood cursing at the car, a wrench slipped out of my cold wet hand and fell across the main ground post of the battery across to the frame of the car, and I was surprised that I saw sparks fly from a ground to ground short.  I removed my Ground cable and cut the sheath off.  Low and behold I found a twisted green/white mess of corrosion about 6 inches back of the Battery terminal. I also had a 4 volt difference of potential
between the Fame and ground on the negative side.

I have also found this on the Main power cables for the battery to starter on my 90 Cabriolet.

Since there were a plethora of ring connectors on both my ground and power terminals,  I used replacement cables that had extra take offs where I could remove the additional wires and crimp them directly to the take offs eliminating the ring connectors.

Just my non-specific take on a extended Start issue with cars in general that I have seen over the years.