Passat b5fl 1.9 tdi avf: Difficulty Starting After Prolonged Inactivity Despite Fuel Changes

Hello, I have a problem with firing after a long break, e.g. after a night or after 10 hours at work. Generally, I had problems before, but I changed the filter and replaced all the fuel lugs plus bands and the problem resolved for some time. For several weeks he would fire normally a few days later, I had to take a few or several seconds to get it wrong. I will add that it was for a small amount of fuel and after refueling it began to smoke normally for less than a week until today when I had to shoot it in the morning for so long that it was almost dead. He lit only a cake from the arrow, even on almost uncharged battery and everything was already ok. After 10 hours at work again the problem lit without a cake but barely. I will add that I now have 3/4 tank somewhere in the tank.

I thought that it could be the fault of the pump in the tank that once works, so when I returned home I listened and always turned on for about 2-3 seconds. So I pulled out the heater and drained off as much fuel as possible, i.e. to the filter and at the first attempts to switch on the ignition with 5 or 7 times in the filter nothing came and the pump was heard.

I started to rummage before the filter after the filter into the bottle and in my opinion the pressure is not too big as the amount of fuel fed each time the ignition is switched on. But after a few attempts, I made everything and then the first time I completed the filter until the fuel was thrown out through the hole from the heater. The pressure on the eye was also different but I noticed that after connecting directly to the pump under the trunk as if the pressure was higher. Is it possible that the pump is run up and does not make the right pressure?

I do not want to buy shelves in the dark tomorrow I will have a pressure gauge and check the pressure, I just wanted to know what exactly should be the pressure at the filter because one is writing with 0.5 bar, the other with about 1 bar and I don't know. And how much fuel should be more or less such a pump with one ignition on

At the end I will add that, except for this firing, nothing more is wrong with it, as it fires, I can immediately put it out and fires from the arrow, it accelerates well, and everything is ok, only the first firing after a stop. This morning, for example, lit almost well I had to turn maybe 2-3 seconds

Buddy, look at the pump supply, maybe the connectors (pins) are tarnished. Check what voltage is actually reaching this pump. Maybe you have a leak in the connection of the fuel hoses, but it's best to remove the pump and assess its efficiency. There is no dirt in the fuel tank and the filter is not "killed". You say something is wrong with fueling the engine, so maybe it goes back to the tank and you should think about a check valve, for example.

I changed the pump in Baku today with a different one and it makes definitely better pressure than mine. We'll see how it will be now but it will be the fastest tomorrow as it stands overnight. I have a non-return valve just before the fuel filter. I just wonder what controls the length of the pump because it works somewhere max 3 seconds and it seems to me that it doesn't work any longer. And I don't know if her work is controlled by ECU or just some time relay. I used to have a bmw e46 2.0 diesel and it pumped there a lot longer on a cold one than on a warm one but here pump-injection and there was a regular pump here can also be like this but maybe someone will tell me for sure. Because at this time it does not inflate too much, from what I read it has a capacity of 80 l / h, that is, it pumps about 60 ml for 3 seconds, which is not too much, so I wonder if it should be that it works so short.

He works long enough. They have all B5's there, it is controlled by the engine ECU. There are no timers.

Well, we'll see if now how better pressure does it will fire. If not, I will only have a vacum pump in the head to check and if it will be ok, I have no ideas

Well, maybe it's better, but today I had to turn it on for a few seconds yesterday morning it was ok and in the afternoon after 3 hours of parking it did not smoke, somehow it had to turn for 3-4 seconds until it got it. I don't know now. Strange that one day is ok and the other day is not. Maybe someone has an idea what could be the reason? Rather unlikely that vacum once worked and not once, or that the fuel once backed up and once not ..

I also have 1.9 tdi and similarly - a powerful battery, it turns, but it does not start immediately. Candles. Yes, always in winter for 7 years. This is probably such a malfunction of this engine, I have the impression as if the fuel was not feeding enough.

And sometimes you smoke well and sometimes bad or always bad?

The shorter the stop, the faster it smokes. Somehow I did not notice that it was better once and worse. I refueled at various stations and fuel also has no effect. I changed the oil to 5W, but I also don't remember any significant difference, and after a few months the oil began to decrease, so I returned to 10 W.

Added after 2 [minutes]:

I start - left on the clutch, right brake and some gas. It seems to help - after a long break. After a short hour, two smokes immediately and without it.

Added after 6 [minutes]:

Oh, and wait for the candles to warm up, i.e. how the candle indicator goes out. Some people write to wait for the candles to "pop" - as if it is always longer than the indicator is lit. I don't see the difference anyway.

I always wait until the relay from the candles breaks, sometimes even gives ignition. And for me it is just like a few days before, even a week or two smokes well half a turn of the engine literally and then one day, two, five different is the problem and again good. The temperature is rather irrelevant because now in the morning more or less always the same from -1 to +4

Well, so I do not have checkered. For example, it seems to me that it burns best after one candle warming immediately after the indicator light goes out. Let me know how I progress.

After work, before firing, I remove the heater from the filter and see if it will be full. But the valve just before the filter also the pump would have to have a leak and remove fuel from the filter or the filter itself but was installed a new one about 3 weeks ago. And yes, I have no ideas where to look and what else I can check

Well, nothing helped further the lottery once smokes from the arrow once after a few seconds and sometimes you can spin until the battery falls and does not catch only the pitch lights. After firing, everything is still ok and then burns to touch.
I don't have ideas anymore .. The filter is full yesterday I checked the candles again and whether the electricity came and everything ok. I ran out of ideas if it was always because I stop, I still understand it, but for example in the morning today without a problem after 9 hours of parking fires from the arrow and after work after 11 hours after a few minutes of mending did not fire from the cake

The problem was finally solved, it turned out that the vacum liquid gently from under the lid from below and it was enough to get aerated. I exchanged for a Bosch golf 5 from 2008 and I have been smoking for a week without any problems, I think it will be ok.