B230K no petrol in carburettor

B230K was difficult to start when petrol evaporates from the carburettor: petrol pump seemed to be not in any problem, yet it will not bring petrol to the carburettor unless the car is started way beyond normal for a car with a dry carburettor??? What is the purpuse and how it works, of the part between the petrol pump and carburettor?
Now it does not want to start at all. If I spray the start-spray or pure petrol through the opening on the carburettor cap (where one of the vacuum hoses is normally connected), it starts immediately and runs few secs, then dies.

How is the small plastic fuel filter before the carburator? Maybe it's full of "junk". Replace it with a fresh new one.

Groeten,
Gerben

Check the electeical valve on the carburettor.

Thanks. I have replaced all the petrol hoses and filter as regular maintenance, and removed and checked the fuel pump, which looked and worked perfect to me, when it was out of the engine. However, between the fuel pump and the carburettor there is one part below the intake manifold, which I did not remove or look (mistake). You can see it here on this pic:
212.247.61.152/EU/ZF0001_bilder/Sprangskisser/1503030110l.jpg
I do not know exactly how it works, I guess it is there to relief the pump and provide the return of excessive fuel into the tank, now I think it prevents the pump to bring the fuel to the carburettor, and instead it just goes back into the tank.
I disconnected the fuel supply pipe from the carb and put it into the bottle, it hardly got few drops after starter motor was engaged (and before disconnection, it was started well too much so that the fuel had to be pumped up from the tank to there if everything was ok...).
Does the car with carburettor engine with mechanical fuel pump has the in-tank fuel pump?
Can I just connect the carburettor to the pump bypasssing the thing between?
If I blow back through the fuel supply pipe, the stream of air just goes freely. If I suck on that pipe, I get petrol in my mouth. But the car wont start.
Initially it was very difficult to start it always when it would be sitting longer than few days. But eventually it will start, then run at 50 rpm first 10 sec, then run perfect, and start perfect. I thought it was a carburettor problem, and when I opened it I spotted there was a problem with the little plastic lever that closes the choke, so I thought that was the problem and repaired that, but the problem persisted. Now, after a month of sitting in the garage, the engine will not work even after it got started trhough injection of small quantity of fuel through the carburretor cap...
<img src="/sites/default/public_files/user12381/IMG38728-20140603-1731.jpg" width="500" height="375" />
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<img src="/sites/default/public_files/user12381/IMG38845-20140606-1417.jpg" width="500" height="375" />
<img src="/sites/default/public_files/user12381/IMG38842-20140606-1416_0.jpg" width="500" height="375" />
<img src="/sites/default/public_files/user12381/IMG38895-20140609-1914.jpg" width="500" height="375" />
<img src="/sites/default/public_files/user12381/dugine_boje.jpg" width="500" height="375" />
<img src="/sites/default/public_files/user12381/vakuumi.jpg" width="500" height="375" />

The motor is still not working.
Looks like I messed up with reconnecting vacuum hoses, so I need to check that.
Also I was not knowledgeable enough about the fuel supply scheme, and that the mechanical fuel pump cannot supply fuel without the work of in-tank electrical pump (I did not expect that the car with mechanical fuel pump will also have an electrical fuel pump). Apparently this Vovo 740 has also electric fuel pump? Isn't that stupid?
I found this on the Internet and will see if it is of any use to check the vacuum hoses:
www.volvoforums.org.uk/showthread.php?t=87269
<img src="/sites/default/public_files/user12381/ti200c.gif" width="323" height="500" />