Bad start Toyota Avensis.

Hello everyone. I have a problem with my birds to see if someone guides me a bit.
The problem is that the car does not start well. When I am going to take it, it is hard to start, as well as 4 or 5 seconds (it has always started like a shot). When it starts, if I stop it and start again, then perfect, nothing else to touch it starts without problems. But if I leave a little time stopped it returns to it. I thought it was for some air in the injection, I have opened the tubes that reach the pump (one in one with the car started) to get the possible air and nothing, it remains the same, I have disassembled the air filter and I have remembered it and follow the same thing, I do not know what to look more, because it looks all of the air in the injection, but I do not give it.
The truth is that it has come to the root of a change of gas-oil filter, but the only thing I think is whether the membrane of the filter will be wrong and suck air out there.
What do you think? Any suggestion or idea?
The car is a Toyota Avensis 20.td (90cv) of the year 1999.
Thank you.

Then it is possible that you are downloading the diesel circuit or you have a burned heater in the car may be that they left the valve in the open filter support or the filter was badly mounted and the air is aspiring if you are not putting that you can put a valve not return a check valve that lets pass the diesel but does not allow it to come back, check the spurion screw If the O-Ring takes it, do those tests and let me know.- Alf

Hello again.
I have checked with a canterors and apparently it gives me that the four (in resistance position, practically null) are fine).
I have reviewed the entire system. I have removed the filter again. The joints are perfect, I have remembered it by pressing the filter well so that it does not suck air. Apparently it was fine because I did not present any leaks but hey, I have filled the filter with the hand pump, I have returned to purge the system opening the gas arrival tubes to the pump. The car has started well, even with two lazy tubes, I have left the Relay for a while. I have stopped it, I have started immediately and perfect, but at the time I have started it again and it has already cost it as 5-6 seconds to start. I don't understand. Could it be the purged manual bomb that it carries? I can't think of anything else.
Any idea?
Thank you.

It is possible that you have the filter escape because if it has been a root of that it is clear I do not know what portfilter carries but they usually carry a rubber that you have to replace them, if they are a cartridge filter, if they are of the other then it is to replace copper washer if it takes them and something else End of the cable in the positive of the battery and the other end with the positive of the battery is giving it in the head of the heated where the nut, well once that if there is a spark

Do that heater test with the current cable disconnecting the cable or the laminate that unites them all or putting the non -return valve of diesel that thus commit you like this the circuit is not discharged