Problem with fuel pump, Xantia won't start.

[jacek2001]

Hi everyone. I have a problem with my petrol Citroën Xantia 1.8 16v from 1996.

The car won't start when I turn the switch on. I check the fuel pump and when the switch ignition is on, fuel pump don't have power but cables from pump to double relay are good.

All circuits are checked, double relay replaced for new one, inertia switch cables stuck together, ignition switch replaced for new one. I swapped the ECU from a similar car for test and the problem is the same.

When Ignition switch is on, double relay plug have power and when I connect two pins together fuel pump is working.

Did any of you have a similar problem? Thanks for any suggestions, Jacek.

[xantia_v6]

Here are the xu7jp4s injection wiring diagrams, which should help.

[wheeler]

Are you getting a good power supply to pins 2,8, 11 & 15 of the double relay?
Are you getting a live feed to the injectors when cranking?

[peter306]

Is it turning over, mine would turn over but not start, crankshaft sensor was faulty.
Peter

[jacek2001]

Hey Wheeler! Thanks for your response. I checked pins 2,8 11 and 15 with circuit tester and all was light on. I also checked ECU with trouble codes and I had only 12 (start) and 11 (end). I don't check injectors, for test I will unscrew spark screws?

[jacek2001]

Hey Peter306, crankshaft sensor is good. I try to start a car with new sensor and problem was the same. I changed the old sensor for a new one because the original was a little bit melted when I burned a clutch on the highway. I replacement clutch witch Haynes manual and after that was the beginning of the problems with starting.

[peter306]

Hi Jacek, by any chance is the new sensor a Bosch, mine was and it was wired up the wrong way round.

[wheeler]

I don't check injectors, for test I will unscrew spark screws?

No, you are only checking for a power supply to the injectors when the engine is turning over. The injector power supply is a shared output of the fuel pump from the double relay.

[CitroJim]

Are you saying the car was starting normally before the clutch change and the problem has only developed since the clutch change?

If so then you have disturbed something whilst doing the clutch... It'll be well worth checking any wiring you may have disturbed during the clutch work...

Does this car have the keypad immobiliser? If so, do you get the green light when the correct number is entered? Or are both green and red lights on at the same time? If both are on then you have an immobiliser problem.

Also, as the keypad code is stored in the ECU, did you use the correct number when you swapped ECUs?

[jacek2001]

I don't check injectors, for test I will unscrew spark screws?

No, you are only checking for a power supply to the injectors when the engine is turning over. The injector power supply is a shared output of the fuel pump from the double relay.

Thanks Wheeler, I understood now. I just now connect circuit tester to Injector plug and when engine is turning over on injector is no circuit.

[wheeler]

Is pin 14 of the double relay & pin 13 of the ECU getting an ignition live feed?
Do you have good continuity between pin 7 of the double relay & pin 7 of the ECU?
If you earth pin 7 of the ECU with the ignition switched on does the fuel pump operate?

[wheeler]

Are you saying the car was starting normally before the clutch change and the problem has only developed since the clutch change?

Also, as the keypad code is stored in the ECU, did you use the correct number when you swapped ECUs?

Both very good questions.

[jacek2001]

Are you saying the car was starting normally before the clutch change and the problem has only developed since the clutch change?

If so then you have disturbed something whilst doing the clutch... It'll be well worth checking any wiring you may have disturbed during the clutch work...

Does this car have the keypad immobiliser? If so, do you get the green light when the correct number is entered? Or are both green and red lights on at the same time? If both are on then you have an immobiliser problem.

Also, as the keypad code is stored in the ECU, did you use the correct number when you swapped ECUs?

Hey CitroJim, all problem was started since the clutch replacement. Before that, all worked excellent.

For now, I checked all electrical plugs and spray them with special spray for electrical connections. 

Yes, car have immobilizer with keypad. On original ECU, after entering code lights only green led. In swapped ecu I can't entering my code, but I remember that fuel pump was started with locked immobilizer for around 5 second.

[CitroJim]

Hey CitroJim, all problem was started since the clutch replacement. Before that, all worked excellent.

Then something has definitely been disturbed or damaged in the process, not necessarily electrical... Maybe an earth wire has not been bolted back to the bodywork or engine or gearbox... A disconnected earth wire can make fault-finding very confusing and perplexing!

Yes, car have immobilizer with keypad. On original ECU, after entering code lights only green led.

That's good! It means the keypad and immobiliser are working properly...

Doing the tests advised by Wheeler should soon reveal where the problem lies...

[jacek2001]

This fault is really weird. 

Double relay have good power supply and when I give ground cable to double relay's pin number 10 ( connected with 52 Ecu's pin) I hear than fuel pump starting, but engine still won't start.

 It's look like Ecu can't give ground to double relay's pin number 10 but why? When I swapped Ecu to similar problem was the same and all ground cables on engine and gearbox looks really good.