My car turns on hardly

Model : CITROËN C3 I (FC_) - 1.4 HDi (68Hp),

I have air bubbles in fuel line. That's why the car turns on hardly.
I use a manual pump to remove air from the fuel line. After I get air out from fuel line by a manual pump, my car turns on.

I change fuel lines .
I Change fuel pressure regulator.
I change fuel filter.
checked all connections .

1.How i can get zero pressure in fuel line?

2.where is fuel pressure sensor location in my car?

3.Is there any difference between fuel pressure regulator and fuel pressure sensor?

Mamal wrote:Model : CITROËN C3 I (FC_) - 1.4 HDi (68Hk),

Its a Diesel. Not a Petrol.

Mamal wrote:I have air bubbles in fuel line.

You have air being drawn into the fuel system.

Mamal wrote:That's why the car turns on hardly.

Non starters can be due to poor starter motor rotational speed, fuel pressure, immobilisation, engine ECU fault and low common rail pressure.

Mamal wrote:2.where is fuel pressure sensor location in my car?

On the end of the common rail.

Mamal wrote:1.How i can get zero pressure in fuel line?

You will get zero fuel pressure if there is an ECU fault, poor starter rotational speed, immobiliser....

Mamal wrote:3.Is there any difference between fuel pressure regulator and fuel pressure sensor?

Yes, 2 different things that are in 2 different places. One measure the pressure generated and one regulates the pressure within specified limits.