9xjs6cyl,

You HAVE to first verify if the pump is running for 2 seconds when the ignition is turned on. And then does it run when the engine is cranking? Otherwise you're just guessing at where the problem lies.

Find a stranger on the street, or a pizza delivery guy, anyone to help you do this! Otherwise you're going round in circles. Nothing in the seat wiring will have affected the ability of the car to start.

Cheers

Paul

 

Paul, I grabbed the kid next door and had him turn the key. I heard nothing from the fuel pump.

 

As long as you are SURE, by testing it with a test light or meter, not just listening to it click, that the relay is good, then the trigger circuit of the relay is not receiving voltage. Test if, when the ignition is switched on, there is voltage to the trigger circuit of the relay socket for two or three seconds.

 

There is something I want ro check before we go any further. Then I will get back with you.

 

So, If I understand what you are saying, Have someone turn the key while I hold a volt meter on pin #85 and #86 in the socket for the fuel pump relay to see if I'm getting any voltage...right?

 

I looked in my manuals for a fuel pump fuse, and I didn't find one. I looked in my manuals for a fuel injection relay and didn't find one. I looked in my manuals for a fuel injection relay fuse and didn't find one.

 

93xjs6cyl,

I've just looked through the documentation.

Volume 5 of the Workshop Manual is the Electrical Circuits & Diagrams. Page 90.5.7-2 (& the page before) shows the diagrammatic of the Fuel Pump Relay & Fuel Injection Relay. Page 90.9 - 5 details the location of those relays.

Pages 48 & 54 of your Drivers Handbook detail the fuseboxes and the relevant fuses. Page 57 describes the location and colour of the relevant relays.

Cheers

Paul

 

I just tested the connector for the 2 second voltage and there is NO 2 second voltage. I even made up a small light bulb with two wires that I put in #86 and #87 and it did not light.

 

Paul, On page 90.5.72 I see the fuel pump relay which is the one I just tested and got no 2 second voltage. There is a fuel pump &RFI module (RH104) but that comes after the fuel pump relay and being the relay isn't getting voltage, neither will they. There is no fuse for the fuel pump or fuel pump relay. Being we are not getting the 2 second voltage, I guess we know where to start looking.

 

When I had the light bulb hooked up to the relay connector, it was not getting any voltage at all.

 

93xjs6cyl,

As mentioned in my post above, the fuses fir the 2 relays are detailed on Pages 48 & 54 of the Drivers Handbook. Are you saying that the fuses aren't there?

Paul

 

Paul,
I have the handbook and the supplement and the fuses are discussed on pages 311-317, so, we must have different books. I did not find a listing for a fuel pump fuse or a fuel injection fuse. As far as I can tell, I only have one relay for my fuel system, a fuel pump relay that I tested. I could not find a relay for the Fuel injection.

 

Greg in France,
I tested the fuel pump relay for the 2 second voltage and I got nothing at all. I even wired up a small light bulb and connected it to #86 and #87 on my fuel relay connector and it did not light up at all. I'm guessing that the 2 second voltage is supposed to come from the ECM. I know the fuel relay is functional, the inertia switch is functional and the fuel pump is functional. The thing is everything was together and working. I started the car several times and had no problems, then it just stopped. I'm still not getting any gas to my plugs.

 

Well, I'm getting to know this car better and better every day. Now I know about relays I didn't know it had and now my seat is working. I'm grateful it didn't leave me stranded anywhere, it was in my garage when it decided to quit. I had to start putting it back together today because it was beginning to look like a parts car (lol). I'm not worried about having to buy a part for it, I just want to make sure it's the part I need and if it's not I guess I'll have a spare. That's not a bad thing for a 29 year old car. I'm also grateful I don't have to work on the fuel pump from hell. Hearing it whine yesterday made my day. I would imagine finding a Jaguar mechanic in this small town would be a challenge. The last time I took one of my cars to a mechanic here, they charged me $500+ and told me it wasn't running right. They had no clue why.

 

Hi 93xjs6cyl

If You are not getting gas to your Plugs, then assuming the Fuel Pump is running 'as you say it is' then it could be one of these things (which is not an exhaustive list) but things that you can try

(1) You may need at least 10 gallons of Gas in the Fuel Tank for the Petrol to even reach the 'Sock Filter' on the base of the Fuel Pump

(2) You might have a Blocked Fuel Filter

(3) You might have Blocked Injectors if your Car has been Standing for some time, though a lot less likely if you say that your Car has been running

(4) A failing Battery never helps as these Cars need a really good 'Kick over' !2v - 13v

(5) Though based on an educated 'Guess' I would say your Fuel Pump may not be 'Holding Pressure' that is a 'Classic Symptom' of Sometimes Start and Sometimes NOT So how do you fix that?

(6) 'The Fix' Please don't go and waste any more money on Mechanics who may not know, as this is a very 'Simple Fix' that almost any one can do with just a Couple of Spanners, as if your Fuel Pump is losing Pressure then you may need to buy a New FPR (Fuel Pressure Regulator) in the UK about £50

Inside the Fuel Pressure Regulator (FPR) is a Rubber Diaphragm, that prevents the Fuel Running Back to the Tank but over time this Diaphragm can get porous and if and when that happens, then it cannot maintain the Fuel Pressure, which then Flows back to the Tank

Sometimes it will and Sometimes it won't hold pressure, just enough to get her Started and once She is running, She 'MAY' keep running 'Till the Next Time' that you Try and Start Her (you just won't know)

Based on the prices you've been throwing out, it will probably Cost you more to have the Fuel Pressure Tested, than to go and buy a New Fuel Pressure Regulator (always a good investment to have a New one)

Then disconnect the Battery if She Won't Start or if She will Start Pull the Fuel Pump Relay and then let her run until the Engine Stops (as you are deliberately running out the Fuel Pressure)

In any event disconnect the Battery and make sure the Engine is COLD (have a Fire Extinguisher Standing by just in case the worse should happen although it probably won't)

Then using Two Spanners (counter torquing them) Carefully loosen the Fuel Pipes on the FPR this is a job that you should do outside as you may get some petrol coming out under residual pressure, so have plenty of old Towels to catch any drips and only remove the FPR Completely, once you are sure that there is no more pressure left in the Fuel Lines or Petrol coming out

The Fuel Pressure Regulator is under the Bonneṭ/Hood

Then just fit the New one and hope you've solved the problem!

 

I am not getting any power to my fuel pump relay. I probably need to figure out why. Once I get power my fuel pump, I should be getting fuel to my plugs.

 

Hi 93xjs6cyl

Have a look at the Photo above (just did a quick edit for you) Inside the Plastic Fuse Box with Jaguar written on it are some Fuses (my car is an AJ16 but might be the same on your AJ6)The Fuel Pump Relay Fuse could be one of those and the location is probably shown on the inside of the lid but I haven't got my Owners Manual Handy to check for you (but could be Blade Fuse 15?) so best check them all

 

Do you have a fuse for a heated Oxygen sensor.
I know on my 94 v12 it was located in the right side of the boot near the boot lid brace.
Small fuse block with Jaguar cover.
When my fuel pump stopped working it took me six months and a Jaguar expert to find the problem.
He spent an evening with the wiring diagram to find the issue.

 

All fuses tested good.

 

93xjs6cyl

Will She run on a squirt of starting fluid