Xu10j2te Wiring Help Please, Got Fuel But No Spark.

[Goliath 94]

I'm getting really fed up with this now, this is the second turbo conversion I have attempted and by the looks of it the wiring will have defeated me both times.....

 

Its an XM engine and loom, I have Fuel signal to the injectors and the fuel pump runs but there is no spark. I have replaced the double relay, ECU with a known unlocked one, coil pack, ignition amp, leads, plugs, and it still wont give me a spark. Does anyone have any idea what might be wrong here?

 

I think we have the correct power to the coil (but i cant remember or work out how to test it, ask WP lol). I have been told that the citroen looms have some sort of inertia cut off switch which cuts the fuel pump and spark if the switch is knocked or turned upside down, I was told this is near the turbo boost controller/solenoid thing on the loom, can anyone confirm?

 

Thanks

[welshpug 1,622]

just to add, when a power probe is connected to the injector plug wire that goes to the ecu, it shows an earth signal flashing when cranked, similarly with the plug for the ignition amplifier, an earth signal is seen when the engine is cranked.

 

there's power to the injectors and the coil pack, so I'm a bit confused!!

[M@tt 77]

My XM turbo loom didn't have this, but Nats that i looked at did. It's one of those big switches with a rubber cover over it, like on a GTI6 loom. it'll be obvious if you have one or not, but that only cuts off the fuel not the spark so wouldn't help you in this case if you're saying you're getting fuel.

 

However the fuel pump and coil are both powered by the same relay in the double relay so if you're getting power to one you should be getting power to the other. However the relay only closes and they get power once the CPS detects the engine is spinning.

 

To test for voltage at the coil check pin 4 of the coil plug when you're cranking the engine.

 

Also hold onto the double relay as you crank the engine and see if you can feel it clicking. It should just click one when you put ignition on and then again once as the engine is cranking.

 

HTH

 

Matt

Edited April 6, 2009 by M@tt

[Goliath 94]

M@tt you legend, although your suggestions didn't directly solve my problem it is now sparking!

 

 

I checked pin 4 of the coil pack plug, there was a constant 6v to it even with the keys out and 12v with ignition on, still constant 12v when cranking. I held the double relay and it clicked once when ignition was turned on and once more when cranking. The relay seems fine but the voltage to the coil pack dosent seem right so I though what the hell, just change the double relay AGAIN anyway, and guess what I now have 0v with the keys out, 8v with ignition on and a switched 10-12v with cranking AND A BLOOMING SPARK

 

Now just to fix the fuel leak and plug the fuel pump fuse back in and see if it fires up!

 

Thanks

[welshpug 1,622]

woo!

[M@tt 77]

get in

[pug_ham 240 3 Cars]

The inertia switch in the GTI-6 loom I have only cuts the fuel pump feed after the double injection relay.

 

Graham.