We have just notice the fuel is flowing through the return line and same time through the main line to the Injectors.

Instead of returning through the return line, is not the case in my car.

Has anyone here experienced such situation?

Where to check to resolve this issue?
what could probably be the cause?

Help needed

Thanks

Mike

I'm not sure what your problem is. The fuel is pumped from the tank to the fuel rail from whence it goes to each injector. More fuel is pumped that the engine uses. Via the fuel pressure regulator, surplus fuel is returned to the tank via the return line. So what is your problem ?

in my case the fuel to the injectors is supplied from the line where the surplus is supposed to be returned.

The return line and the main fuel line that supply the fuel rail flows parallel in supply the fuel to the injectors instead of them flowing in the opposite direction.

Hope you get me now?

Hi Mike. I'm not an expert on Jaguar fuel injection, but just just thinking it through mechanically.

Are you seeing pressure (flow) from both lines on "out" side of the regulator? The pressure and return lines only come together at the regulator, bad regulator possibly. If you have disconnected the press/return lines before the regulator and have fuel gushing out of both lines, someone has done something terrible with the line plumbing. Does the engine even run with this condition? What does the pump sound like, is it straining, does it blow the fuse? Is there a connection between the tank and regulator that is leaking that didn't used to leak? These would be signs of the pump over-pressuring the system because the regulator is not providing a return for excess fuel. Is this something that has just happened to a car that has been driven without problems before, or one of the cars you've just acquired recently?

Sorry I can't give you a definite "here it is", but maybe these thoughts will help.

Hi boss,

There is a pressure into the regulator from the return line instead of out.

this is my first Jag with tones of issues I have been posting here. I have been driven this car with low engine performance, we earlier saw the fuel does not return to the right tank when switch tanks.

today the car failed to start we tried to figure out what the issue might be only to discovered this issue.

The regulator on the car is a brand new I purchased from SNG couple of months ago earlier this year.

With the two newly acquired JAGs, one run and drive the other was fork lifted. The fork lifted one has a fuel line rusted and broke so am yet to check on that to find what are the other issues with it.

myself and the mechanic will investigate to find out why this issue happened.

VERY unusual fault ! I think I have never before seen a similar report on this forum, or indeed on any forum, nor whilst I was running a 1980 Series 3 back in the 80/90s. It does sound as if Charlie Allthumbs has been working on your car before you got to it. It does sound a bit dangerous, too, because the system relies on maintaining the allowable pressures in the fuel rail. I once had a seized regulator and fuel started to leak out due to excess pressure.

What is the name of this valve and where can i buy please?

I will ask David of everyday XJ6 if he has it.

Air bleed valve.

#3 in this illustration

https://parts.jaguarlandroverclassic.../brand/jaguar/

Cheers
DD

Thanks Doug

Open the gas caps. if the pump is delivering gas and the engine is running, you should see fuel being returned to the tank.

WAG. Fuel being forced back through the return line? I can not fathom, how!!!

Carl

It's a mystery to me as well, Carl.

Since Mikega asked about the air bleed valve I assuming that he suspects (or has perhaps even confirmed) the pressured fuel is taking a path through the bleed valve and into the return lines?

Cheers
DD

Replacing the Air bleed valve has solved this issue now.
thanks to everyone for support