Citroen Zx 1.4

[tommy]

Citroen zx 1.4 petrol. When engine is warm the car starts to run very poor as if it has a flat spot or dirt in the fuel. Changed coil pack 1 and 2 spark plugs and leads injectors have been replaced as well

and a compression test has also been done. still no joy? Any ideas.

[Shemer]

Did you check the colour of the spark plugs?

 

If they're white (not light tan, white, check in the following link):Spark plugs guide , then it means you have lean mixture.

 

Assuming no compression problems (as you wrote), and parts you stated already replaced, I would go for checking the fuel pressurein the system.

 

If it's a single point injection, then pressure is ~ 1.5 bar. for multipoint - ~3 Bars.

 

If it fails (make sure the engine is warm, where the problem appears), then main suspect should be fuel pump (especially for multipoint). Next one is the fuel pressure regulator.