Vx fuel circuit

[Fingers]

Seems the fuel problems hit everyone at once, I'm having trouble getting any fuel to the carb. Here's what I've done so far, found that when the ignition's on just before starting there's no power to the pump which is what I expect, when I turn the engine over it gets power for a second or two then nothing, and doesn't seem to be getting enough power to pump fuel. I've bypassed the entire circuit and the pump runs and pumps fuel fine. I believe the problem is either a bad earth or the part of the circuit that cuts the fuel flow if there's no spark being generated.

First of all I need a Vx specific wiring diagram if anyone could help, or if anyone knows this circuit and where the signal comes from to tell the fuel pump when to run. I think it's probably just a small fault with a connector somewhere around there but I don't know the circuit well enough, I've followed it all around the engine bay, under the dash and back to the pump


Please help, I really want to drive my baby, she's been off the road for two weeks and the withdrawl is killing me.

[A1.6HPE]

Hello Fingers,
I have never worked on a VX engined car but I do have a copy of the supplement for the workshop manual. Unfortunately there is no wiring diagram, only a picture and a description. The system seems to be setup to avoid the fuel vapourisation that the VX engines can suffer from (however I have never heard any complaints about that). I am assuming that your pump is actually running OK, and there does not seem to be any control circuit for it (either on with ignition of off). The fuel flow is stopped by a solenoid valve mounted on the offside brace from strut top to bonnet hinge panel (right hand from drivers seat). The valve is controlled by a relay that is in turn controlled by a bi-metallic switch that is in the fuel supply pipe (between the valve and the carburettor). The valve is normally open and cuts off the petrol supply if the temperature of the petrol exceeds 70 degrees celsius. So your problem could be that the cut off solenoid is being activated due to a short to ground in the connection between the controlling relay and the bi-metallic switch. The control relay is behind the offside headlamps and there is an in-line fuse holder. Try removing the relay - that will prevent the solenoid cutting in.

I will get the notes and diagram scanned - hopefully tomorrow.

Leo

[Fingers]

Yeah I know exactly the circuit you mean, I've already bypassed that with no difference noted. I also just remembered that I have the VX factory service suppliment too, mines got a wiring diagram but it's for the Trevi VX, but I'd say it's pretty close, will go and have a look right now.

[rossocorsa]

http://www.lancisti.net/forum/modules.php?set_albumName=albuo21&op=modload&name=gallery&file=index&include=view_album.php

[Fingers]

That's fantastic, thanks so much, that's saved me a lot of time, it would've taken me ages to find which relay was which. I'll be printing off a copy of that.

[A1.6HPE]

Hello Fingers and Alan,
It would be good to get a wiring diagram "up here".

Leo

[Fingers]

Could someone please tell me where the oil pressure switch is, I think this may be the problem.

[Fingers]

And yes it was the problem, well actually it was the top quality Italian electrical connector the the oil press switch, but MUCH thanks to rossocorsa for the link to your suppliment, it was the relay diagram that pointed me straight to it. Thanks so much, now I can take it away on my summer holiday next week! I'm so pleased.