Air in the fuel system leads to loss of power, traction of the car, and can also negatively affect the operation of the fuel pump and the entire engine. In this case, it is not always possible to see blue or black smoke and hear the unstable operation of the engine, the so-called triple. Depending on the amount of air incoming into the fuel system, the engine can begin to trip at an increased speed, and on an idle run without a problem.

I’m not an auto mechanic especially for diesel engines, but some procedures for identifying faults can be done by self before going to the service station and you can save some money because the cost of repairing diesel equipment is expensive and a simple removal of fuel pump costs a lot of money.

Let us pass to the most important, in this case, these are the signs that show the air entering the fuel main.

– Blue or gray smoke

– it may not be, if air is not enough, or the engine is running at idle, most often appears on the elevated almost at maximum, at maximum speed, black smoke can go.

– Power drop, thrust

– the car disappears the dynamics of acceleration, does not accelerate to the speed at which it could go earlier. Maybe just do not go more than 70 km / h, because the revolutions do not increase. With this problem, it is also necessary to check the EGR valve.

– Short-term loss of traction at speed

– a feeling that someone pulls the tail, brakes, occurs in a fraction of a second to a maximum of gas. This also happens with a faulty injector.

Check the presence of air in the system is very simple, you need to change the standard fuel hoses to transparent (before the fuel filter and after). Below in the video, you can see the air in the fuel system Hyundai H1 (Starex) 2,5TD (engine D4BF).

It can be seen that there are a lot of air in the fuel supply hoses, but you can hear that the engine is running smoothly without a trip and the most important thing is that there should not be air in the system at all. With increased speed, the amount of air increased and at a certain level, the engine started to triple with the emission of blue / gray exhaust gases.

In this particular case, air sucks through the fuel pumping system in the fuel filter housing. The first sign of a malfunction is that swapping can not pump fuel into the fuel filter. Needless to say, it is necessary to check all the connections of the low-pressure fuel line, that is all up to the injection pump.

The photo shows possible locations of air entering the fuel main.

When replacing standard fuel wires with transparent ones, observe the utmost care and attention, before installing new transparent hoses, check for debris, chips or anything like that inside the hose and pour a little through the hose with clean diesel oil after filtering, then install hoses and tighten the hose clips .

After installing the filter from Volkswagen T4, the air is completely gone. At the same time, the car with air suction has not traveled much faster than 70-80 km / h (the speed of the vehicle fell and fell gradually or jerkily), and after eliminating the problem it accelerated to 140 km / h without problems, which can not but rejoice. The whole operation took no more than 2 hours. Ultimately, the body of the fuel filter needs to be replaced.

After the resource of the filter from the T4 came out I installed an original new filter and a new manual swap pump (which also happens to be a casing or filter housing). For correct use of the pump when the fuel filter is installed, it is necessary to unscrew the air outlet bolt on the pump and always pumping continues until the fuel is completely filled in the filter, this will be noticeable when the diesel engine exits the air outlet. To control the air in the system left transparent hoses.

If the manual fuel pump does not work normally, this already indicates a possible problem with air intake system.

I hope this information will help you in solving problems with the car.