Hello

I am new to this site, and am in a bit of a pickle with my 2.5l petrol X-Type!

I have owned it for 8 months, and have had no real issues with it that I could not sort myself, but this one has really got me stuffed.

The issue is that the car cuts out, at fairly regular intervals when run on petrol, but can be started up again with no issues. It then runs for a short period then cuts out again. It does not do this on LPG, only on petrol.

To give a little more information. If I start the car and leave it idling, it will run for 5 mins from cold, or 1-2 mins from warm, then splutter and die. If I drive the car, it will drive fairly normally, albeit with a significantly reduced power, but as soon as I have to brake, and the revs drop down to around idle it dies.

What I have done (or more accurately what Cov Cats in Coventry UK has done who have been extremely helpful and I would recommend to all) to try and diagnose the issue is:
Taken codes from MIL light - shows low fuel pressure code
Replaced fuel filter
Replaced fuel pressure sensor
Blanked off return line on fuel system to tank (put in for LPG conversion over 8000miles ago and worked perfectly when fit) and tested fuel pressure. This shows interesting result of getting max pressure from fuel pump for 1-2mins (around 55 bar?) followed by a progressive drop in fuel pressure until the engine cuts out. The engine only starts spluttering when the fuel pressure drops.
Replaced Fuel Pump - after reading that they can be dodgy in X-Types.

None of these replacements have brought up any joy. Looking in the fuel tank when the pump was replaced, it was clean, no sediment to block the pump/filter. Before anyone starts blaming the LPG system, I cannot see how the LPG system could cause this, as when switched off and the return line blanked off, the original petrol system still misbehaves.

Also, before anyone asks who is not familiar with LPG, I need the petrol to start the vehicle. Without petrol, the LPG will not run the cold car, as it freezes in the lines.

Before I take this to the dealer, anyone got any ideas?

 

All

In the interest of no-one else having to go through the pain that I have had to, let me give the solution to the month long problem...

Battery!

It makes sense really, was cutting out at idle (when the alternator is running slowest and produces least power) the LPG unit was drawing power as well, it is winter at the moment, therefore I am drawing max power to heat windscreens to remove frost...and the b****er who owned it before me decided to put in a smaller battery than jag stipulate (I have just placed in an 800amp battery, correct for the vehicle, whereas the one I just removed was only 600amp! Was a visibly smaller unit)

Hopefully this will help out others who may go through the same pain...especially if the wrong battery is in the car!

Regards

Alex

 

Welcome to the forum Alex,

Good to hear you found the solution. Incorrect or failing batteries are the number one cause of weird electrical and running issues reported across the Jaguar model range here.

When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST section and post some info about yourself and your vehicles for all members to see. In return you'll get a proper welcome and some useful advice on posting to the forum.

Graham

 

I also had a similar problem and it appears to have been caused by the Fuel Pressure Sensor.
When on LPG both Petrol and LPG are being pumped however only the LPG goes into the engine.
The build up of pressure on the Fuel Regulator (for Petrol) has caused it to go faulty.
Unfortunately on my chasis it's a small part but you cannot buy just that bit, bad design by Jag means you have to buy it as part of a bigger section. Cost me £1,000!

 

Ouch!
Sorry to you guys for the pain and dismay.
We can all learn form this especially where LPG is concerned as many people look at LPG as a preliminary alternative to petrol and yet I heard just the other day that LPG garages are relocating/closing down in some areas due to lack of business. A big thanks for sharing that too!
Yep, I'm still learning, damned if you do and well I'll be .....
We live and learn but it's nice to have fun too, Good luck fellas!
Regards, Stu

 

Hi Alex

Thanks for your response.

Your LPG conversion should have a return line for petrol from the fuel pressure sensor (located on the end of the fuel rail) back to the petrol fuel tank. There should be a solenoid on this line to close off the return line if running on petrol.

The hole for the return line should be of sufficient size to 'replicate' the rate of flow through the injectors so as not to throw off the adaptive fuel control.

Without this return line, your adaptive fuel control on the X would be thrown off and you should get a MIL light for fuel pressure high.

Do you have this?... otherwise you will undoubtedly have the problem again.

 

Unfortunately no, it doesn't have it so yes I would get the same problem again and have to replace an expensive fuel rail.
My LPG installer have just spoken to the LPG kit suppliers and they now have an emulator that is wired into the fuel pressure sensor to 'trick' it.
Not sure exactly how that would work but they are aware of the problem and that should prevent it happening again.
I did suggest that they do a mod to redirect the excess fuel back to the tank but they have have this emulator instead.
Fingers crossed.

 

Dear Alex,
As I see, this article is 2 years old and wondering, the battery change has fixed the problem? I have the similar X type with LPG and the same symptom. When running on petrol, the engine dies after couples of min but running well on LPG.
Sabi

 

Maybe I can help you vozarsz

As said before on the X-type there are 2 solutions for this LPG/Petrol problem.
Solenoid on the petrol rail redirecting fuel to the tank
Fuel Pressure emulator
In my "extensive" experience Emulator are a waste of money and a source of problems.
If you do not have a fuel return bypass (or an emulator) you will keep having those problems.
It is not a difficult job and your installer should be able to implement it.
If you (or the installer) need more info on the process I think I should have the configurations somewhere.

Regards

 

Hi Amcastro1,

All my best wishes for 2016.

I have some problems with my 2003 Jaguar XJ 4.2 NA.

https://www.jaguarforums.com/forum/x...2/#post1375651

In this x type tpic ( https://www.jaguarforums.com/forum/x...-petrol-92493/ ) you said "If you (or the installer) need more info on the process I think I should have the configurations somewhere."

May I have more info on the process please?

Best regards
Chris

 

impianti GPL e metano per l'autotrazione Petrol Pressure Emulator

PRESSURE EMULATORS - Various emulators PRESSURE EMULATORS : AEB Alternative Fuel Electronics