Ok, I'm about ready to replace the EFI hoses. Since my manual hasn't show up yet, is there a link or a good description to pass along concerning how to depressurize? Kirby talks about cutting into a hose and aiming it into a container, but I'd rather have a more descriptive view of how this should be done.

Thanks,

John
1987 XJS V12, 62,000 miles

 

Cutting any hose will do, but cutting into a hose is what is required. Make sure work lights are out of the way.

 

I think the official and safest method is to pull the pump relay and crank the engine.

FWIW, I just crack one of the fuel fittings a fraction of a turn and wrap the joint with a slew of old rags to keep the fuel from spraying all over.

Usual warnings about raw gasoline, fire hazards, etc.

Cheers
DD

 

Thanx for the thread as I want to change mine.

 

why does everyone alway say pull the fuel pump relay?? Is that not the purpose of the fuel cut-off switch??

Can you just hit the switch and try to start the engine a bit til theres no fuel left.


Btw keep plenty of water around, at least a cup or bottle nearby. If you don't know all you really need to do when you spill gasoline is douse the area with water and the fire hazard is pretty much gone.

I haven't done this before but I would say disconnect the ends of the fuel rail to depressurize and this will also let you remove it to replace all the hoses on a bench instead of cutting and replacing in the car.

 

Maybe becuase that's what the Jaguar manuals say? I dunno. Obviously I have my own methods :-)






As designed, the purpose of the inertia switch, if that's what you're referring to, is to cut the fuel pump circuit in a crash. The button is to reset it afterwards

But you can use it as a convenient cut off switch if you like





As I recall, subject to correction, some cars are wired so that tripping the inertia switch also incidentally disables the starter circuit


Cheers
DD

 

I recently used the method of lifting the fuel cutoff (inertia) switch, then cranking the engine for a few seconds. Worked fine on my facelift XJS. After finishing the fuel line work, I made sure the switch was reset and back down in position, and the engine started on the 2nd crank.

 

Replacing fuel lines is my next (but not pressing) project on Convertible.
Had to do this on 91 Coupe and it really wasn't difficult. Taking the whole rail off and doing it on the bench is the easiest way go except trying to line up all the hoses/injectors when done....causes outburst of profanity and makes the dog jumpy :-)

 

I do it the fuel pump relay method. I even got a bit carried away and wired a switch in to the power feed to the relay so I can just flip the switch off when I need to depressurize the rail.

 

Well, the inertia switch method didn't work for me, it disabled the starter from cranking (and possibly other things). So I cut into one of the front hoses, and it was fairly uneventful.

The hose that was on the injector was rated for 50 psi, and had the type of clamps that have slots on them on every hose, both on the injector and fuel rail sides. Nice. Anyway, the hose is getting replaced with 150 psi Gates hose.

Is there any reason not to paint the fuel rail (other than the connections of course). I'd like to jazz it up a bit, but don't want to pay for electroplating it with something.

Thanks,

John
1987 XJS V12, 61,000 miles

 

Clamps not needed at all. The nipples are barbed to hold the hose on. I use a spritz of silicone spray to ease the pushing on of the hoses.

Can't see any reason not to paint the fuel rail if it strikes your fancy.

Cheers
DD

 

I have a 99 VDP and I am going to change the fuel pressure regulator. First, I want to depressurize the fuel line, but do not know where the fuel cut-off (inertia) switch is located. Can someone tell me where it is located?

 

Post your question in the correct section...."X308" in your case....to increases your chances of better/faster replies :-)


Cheers
DD

 

agreed. While its possible its in the door jamb of the drivers side like on the XJS noone here would know for sure lol.

 

Will do - thank you.

 

i did this to mine a while back


these are the later ferrule type connectors, no jubilee clips on these, push fit only


ready to go onto the injectors


BB

 

what size are the lines crossing over from rail to rail on the 1992 on up to the 1996?

I need to replace mine as the back one is cracking and splitting...

1/4 3/8 or 5/16 ? I can pick the correct one up on the way home from work...

 

What would happen if you 'didn't' de-pressurise the fuel rail?

 

They are definitely not 1/4". When I replaced those two hoses I couldn't find a definitive answer on the size beforehand so I removed one and compared it to a 5/16" and a 3/8" gates barricade FI hose. Memory fails me on which one I went with, but seems like it was the 5/16". O'reilly auto parts typically has both of those hoses for sale by the foot. It's been a few years and I've had no leaks or problems.

It was quite a chore to cut the old ones off the barbs without nicking the barbs. Use a sharp exacto knife or similar and saw away gently; at some point I recall facing the blade up and cutting upwards to get through the strands in the old hose to avoid nicking the barbs.

Here's a note on the original part number and possible replacement if you want to go the route of a genuine Jaguar part:

JCNA Forums - Jaguar Clubs of North America

 

at pressure fuel would spray all over the place.

I did it once, changing a fuel filter and it sprayed directly into my eyes. It took 10-15 minutes of flushing to get it all out. Don't learn the hard way.