When I drive the following has becoming more regular. The car will start to "cough" and nearly cut out when use the left fuel tank, worse under acceleration. I swap to the right fuel tank and all is good. I recently changed left tank the fuel sender and inside of the tank it was nice and shinny (couldn't see any rust).
I do not think the timing or fuel mixture is wrong as I can drive around normal with no problems, when using the right fuel tank. I tested this up a decent 4-5km hill (Willunga Hill for anyone who lives or been to Adelaide). Because it runs fine with the right tank, I feel the spark plugs will be okay (haven't checked yet).
The car is a Daimler 4.2l 77, I believe with the submerged fuel pumps -see picture?
If it is the fuel pump, is it okay to change or best left for someone experienced? I have attached a picture of what I think is the fuel pump?
Regards Clayton

behind wheel

 

Clayton,

Late as usual??
Its been 25 years since I did this.

OK to change yourself IF the petrol fume precautions are followed.

Memory, hahaha,
Access from a panel in the wheel arch area for the front of the tank. Tank unit is via the tailight aperture.

The supply line coming out of the tank, just under that access panel, has a one way valve in it, and I would check that carefully. The pump dying is still my best guess, but those valves can, and do, stick, reducing fuel supply to the carbies.

 

Did you say you replaced the submerged pump? Will the car idle properly for some time with the right tank selected?

 

All good, I was away on 2nd half of the weekend.
I'll try and have a look at the one way valve (I have a Haynes book and it does have a diagram of what you have described).
Hopefully that's what it is.
If I was to replace the fuel pump would the part be CAC3552? - its my left tank .

Saggy Jag no I replaced the fuel sender as the fuel gauge wasn't working, it now is (via rear tail lights). I suspect I need to replace the submerged fuel pump.
I have tested the fuel sender. I filled the tank and drove as much as i could bear the, observing the fuel gauge reading full then going down as it should.

Thanks

 

Have you checked the fuel tank filter? The symptons you describe are typical of a partially blocked filter starving the engine especially under high fuel demand
I have seen the "in tank" filter getting blocked on several models of Jaguars eg MK1,Mk2, and S1,2 XJ6.
I would drain the tank, remove and inspect the filter.
In my experience the rotary in tank pumps seem to either go OK or fail totally with no in between.

 

Hi Bill
No I haven't checked the in tank filter, Ill will try that . thanks

 

Do you have a diagram or picture of the "in tank fuel filter"? Do I need to take the fuel pump out (I haven't done that yet )?
I have drained the fuel from the bottom of the tank and the fuel was pretty good. The was a little bit of gunk around the drain plug/ bolt but I have cleaned that and when i put my fingers inside the tank didn't feel any more gunk.

 

Hope this helps
You need to undo the big nut C44665 to drop the filter.
Just undoing the small drain bolt SH60504 doesn't allow you to check the filter. which will typically gummed up with sediment on the outside of the filter
Cheers

 

here's a few photos from my 77 XJC. I have many more if you would like to see them. I pulled the tanks and cleaned them, so obviously know the pump, back valve and senders.

 

The diagrams and pictures help heaps, makes sense.
I removed the big nut (C29445) when I emptied the tank (couldn't undo the smaller one), but it didn't have the fuel filter (C29445). I felt inside and could not feel it, although I believe I felt the material part of the fuel pump.
I have seen the new pump from the 3rd picture when looking on the internet, I think the part is CAC3552.
I will try with ordering a replacement pump 1st, if that doesn't work I will tackle the one way valve.
If you have any pictures of swapping the pumps over?
Thanks

 

This is mostly about fuel pumps. I have some more tank removal photos if you go that way.

 

Thanks Geneo, very helpful.

 

Howdy, an update.
I just had the car serviced by my trusty mechanic (new accelerator cable, gearbox service with new change cable and bands checked). I asked him to have a look at the fuel pump, sure enough it was stuffed.
He had also trouble with the one way valve and issues with getting the right fuel pump. Even using his supplier the pump wasn't like the original, and had to do some slight changes. After fitting it and replacing some of the fuel lines it now runs perfect.
He also adjusted the fuel sender wire with the float, as it wasn't reading correctly - interesting as I replaced it using a reputable supplier.
The car is so much better, changes gears smoothly, drops gear down when i floor it and no coughing - feels like I have received extra 10% horsepower!!
I am glad I asked him to fix the fuel pump as it wasn't a simple swap.
cheers clayton