Hey!

I'm having a hard time finding information on this so I thought I'd get my butt into this forum and ask you guys. I don't quite understand the fuel system on my S-type 2001 3.0 V6. I had my fuel pump module (along with pump) changed a month ago, and discovered that there's sort of a second one on the drivers side as well. Why are there two?

Reason why I'm asking is because after I changed the entire fuel module/pump, the car shows that there is more fuel than it actually is. The other day I discovered that when I'm at 45% fuel and make a sharp right turn, the car temporarily loses acceleration and sometimes even dies on me. Surely it can't be the fuel gauge, but what if the other old one isn't "matching" the other one and maybe the communication between these two somehow fail? Any ideas? When car shows 30% on the dash, then the tank is almost empty.

Thank you in advance,
Alexander.

 

The 2nd pump is a transfer / jet one and I think "just" pumps from side to side - when working.

(Later cars can see the two fill levels via ETM but your car is too early for ETM, sadly.)

 

Yes sounds like your transfer or jet pump is bad as JagV8 said above. I would just plan on replacing it.
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Oh so that's what it is.. thank you for quickly responding guys! I will look at it and replace it as well and see if it solved the problem

 

To help understand.
There is only one electric pump to send fuel to the engine.(right side of 'saddle-tank')
The 'transfer-pump' or jet-pump constantly moves fuel from the left side (no electric pump) to the right side to keep the level full on that side.

The two fuel level senders are set to AVERAGE to two levels on each side of the saddle tank.
.pdf from my training class student guide.

 

Thank you for the PDF, it made me understand the system better. So in other words, the LH fuel sender is bad and needs to be replaced in my case?

 

The 'jet-pump' might just be 'clogged' with debris.
It might be broken?

The only moving part of the jet pump assy is the parallel pressure relief valve.

 

Will take a look at this today and come back. Is there any way to check if it's completely broken? By default I assume the left side of the tank should be full compared to the right one if it's indeed broken?

 

It could be, at least the new sender. And don't call me Shirley.

 

The $64,000 Question:

Why was the pump module replaced? What symptoms were present? I'm just wondering if there may have been some other fault present, in addition to whatever led you to have the pump module replaced. A little history would help.

Do you know if the shop did anything with the module on the left side of the tank? If they didn't touch it, it seems very unlikely it would suddenly act up at the same time as the module on the right.

This thread has some details about how all the components work together:

https://www.jaguarforums.com/forum/s...estion-266566/

Here's an excerpt from the training manual, which may have already been posted:



Note the "fuel reservoir" which surrounds the RH pump module. A jet pump on each side of the saddle tank keeps this reservoir filled, to feed the single electric pump. You had mentioned the engine starving for fuel in a sharp corner. That would make me think the reservoir is not being properly refilled, for reasons still unknown. Considering there's a jet pump on each half of the tank to do just that, it would be very helpful to know if the left side was touched at all. If there was something wrong with the new module's jet pump, the reservoir is only being refilled at half speed or less.

 

I will try not to call you Shirley. Lol.

The reason why the fuel pump on the RH was changed was because the dealer I bought the car from messed the module up (the tightener caps or whatever they are called, for the fuel lines were broken and fuel was leaking because of that). Also the pump was going bad, as the car died after 20 minutes of driving. So he ordered a new fuel module with pump, and I replaced it myself because the procedure was very simple.

The LH module/fuel sender/whatever, was not touched at all.

I just inspected the LH and that side of the fuel tank is completely full, while the RH is right now half empty.

 

I just checked the LH module, and I noticed there was some grey/silver goo on the electrical connector so I tried to clean it off with some elctronical cleaner just in case it's doing something.
The second photo; the black and green line is constantly pouring fuel. I took the fuel pump fuse out and cranked the car to release fuel pressure but this one is constantly pouring gasoline. So I can't disconnect it and look at the module properly. Also I noticed that this LH tank is entirely full, while the RH is only half empty (showing about 75% on the dash right now).

Any ideas?