Shouldn't be a hard one to diagnose. Just got my 2001 jag back it's the 3.0 but it's developed a problem. At first start its absolutely fine but after 2-5 minutes it starts losing power especially on hills and won't let me accelerate at all. Turn the car off and on and the problem goes away for 2-5 minutes. It's not a shifting problem it happens and in all gears and doesn't knock itself into neutral just stops accelerating and gets a rough idel sometimes I've been able to accelerate out of it but not common especially since the problem is more prevalent at 55-65mph no matter the gear. Was thinking it was the egr or pcv valve but wanted a second opinion. Btw no check engine light ever

 

Use a smart phone with the Torque app to check the fuel pressure.

How many kilometres/miles are on the vehicle?

Have the ignition coils/spark plugs been replaced?

 

Honestly have no idea on the history, it sat between 2019 and late 2022 after the fuel pump went out with the previous owner. And miles are right at 198,500 miles. How does that torque app work would I need a OBD2 for that?

 

If you do not have a firm handle on the service history of your S-type, changing the fuel filter (hidden behind the LF inner wheel well liner) is always a prudent thing to do...

 

Download the Torque app from Apple or Google and install. Obtain a Bluetooth interface such as the Elm dongle and connect it to the OBD port on the car. Connect the app to the Bluetooth interface through the smart phone and add your vehicle's info on the app. Once installed, you can read many functions in real time.

 

I just did that in October along with the fuel pump and whole system flush with the fuel system

 

Here's a video of what it's doing

 

What’s with the fuel quantity? The tank is practically empty.

The pump could be cavitating when you accelerate or make a sharp corner.

 

It's been doing it regardless of fuel quantity. Most I've put in is 3/8s of a tank so far since I just got a new key made not a week ago and haven't driven it far. But honestly I think I'll try adding more fuel in real quick and see if it changes

 

The tank is shaped like a saddle. The electric pump is on the right. A venturi arrangement transfers fuel from the left to the electric pump to feed the engine. If not transferring properly, the electric pump can run dry.

Definitely check the fuel pump pressure as previously suggested. These pumps are notorious for failing after long periods of inactivity.

 

Will definitely try, car sat for a month after the my buddy who bought it off me died but it apparently had the same problem prior just never experienced it. Will giving it a full tank tomorrow my rear lights are having some problems tonight

 

You need to scan for codes? Posting video's of what the car is doing is of zero value.
Do you have a scanner?
What scanner do you have?

If none you can get the codes read at most auto parts stores in the US. Post back with what you find.
.
.
.

 

At least get an elm327 & use torque!

 

Any updates? The suspense is killing me.

 

Yes sorry for the late update I was helping my buddy move to Austin. Basically it's 100% a fuel problem I used a buddy's OBD2 and it showed no faults at all. But I went to get gas and the problem with it loosing power was extremely prevalent even down hill which the jag doesn't usually have a problem with. Got there and put about 4 gallons in. Car ran absolutely flawlessly all the way back which is all up hill for about 7 miles except when the going around 90° corners which it would lose power again probably from fuel sloshing. Also side note I figured out it runs out of fuel at 15 miles of range completely different from my xj8 that I pushed to 40 below empty one night when I couldn't find an open gas station. Would there be a known fix to this it's kind of a pain to try and keep a full tank in the car at all times

 

As mentioned above, the tank is saddle shaped, so if you has basically run things dry, you are going to need more than four gallons to allow the fuel to flow over and refill the left hand side of the tank.

Also, your fuel pump is liquid cooled, thus running the car with minimal fuel on board will materially shorten the life of the pump.




Go on, be a "big spender" and fill 'er up...

 

Sounds like you have correctly diagnosed the problem. The next step is to decide what do you want to do about it.

1) Do you want to get into the tank and carefully tweak the fuel level sending units so the car runs out of fuel precisely when 0 miles of range is displayed? In my over-inflated opinion, this option is a LOT of extra work with virtually no upside.

2) Live with this minor variation and realize you've been expecting WAY too much accuracy from the system, far beyond how it was designed. This option appeals to my lazy nature.

Personally, I never go below 75 miles range remaining. No point in pushing my luck or sucking up any potential debris sitting in the bottom of the tank.

 

Absolutely right!👍 One should NEVER run a fuel injected car out of fuel; it kills fuel pumps and their associated relays and wiring. Save money, buy more fuel😄.

 

[QUOTE=Sportston;2634761]Absolutely right!👍 One should NEVER run a fuel injected car out of fuel; it kills fuel pumps and their associated relays and wiring. Save money, buy more fuel😄.[/Q definitely not especially since I just fixed the fuel pumps the odd thing is between 70ish miles of range and 15 it'll have problems like it's out of gas but once I reset the car they go away still trying to figure that one out

 

that's what I've been doing I just honestly forget to sometimes I get use to the fuel gauges on my s type r and xj8 and then I drive the V6 a little too hard around a corner and it starts stalling out. It's the backup backup jag I've been molding what I wanted a pre facelift to look like