Please advise.My STR (2003 - 52000 miles) has been sitting at the Jaguar dealer for 2.5 months to replace faulty gear lever assembly.When they eventually replaced the part (refurbished I think) and fired up, they had misfire on two cylinders. They gave me the codes (P0306, P0308, P1314, P1316) It seems (I am trying to find out) that after replacing all plugs and one coil they may now be blaming the injectors (which were refurbished only 600 miles ago). Last year they had the car with them sitting for 7 (yes seven) months to fix a P0171 leak (during which time they replaced virtually everything including plugs and refurbished injectors). Am I correct in thinking that the long periods the car sat unused could have caused the injector and other problems?

 

It may be time to seek the advice of a Jaguar main dealer, or a Jaguar specialist as it appears they are guessing and replacing parts.

The very first step in diagnosing the issues causing the DTCs to set is determining the available battery voltage. With the ignition in the OFF position for at least 30 minutes, there should be at least 12.6 volts available when checked with a voltmeter across the battery terminals. If the voltmeter shows less than 12.6 volts, the battery should be charged for three to five hours at 2 to 5 amps and retested. Insufficient available voltage can cause random DTCs to set and instrument cluster warnings to display.

If the battery voltage is at or above 12.6 volts, then proceed to check the fuel pressure. With the ignition in the ON position, prior to engaging the starter motor, there should be at least 3 bar (300 kPa) of fuel pressure. If there is less fuel pressure, the fuel pump may be failing. It's not uncommon for a fuel pump to fail if the vehicle is unused for extended periods.

 

Thanks NBcat
It is a Jag main dealer who admitted a lack of trained technicians, and I'm sure you're right, guessing..
Not much I can do. I'm in their hands.
I am trying to find out if others have had ignition/injector problems after a long period of the car sitting unused, unless I have to dispute a big bill.

 

I personally have not seen an issue with the fuel injectors unless the fuel has oxidised and has gummed up the injectors. More commonly the fuel pump fails after extended periods of storage.

 

+1 on that. I agree it is unlikely to be an injector fault, least of all two at the same time. Follow what NBCat suggests.

 

They sound hopeless: slow, expensive, clueless on diagnosis. Changing all the coils or injectors makes no sense.

 

You hit the nail on the head!
But unfortunately I'm in their hands, and there are no real alternative options in this part of the world.
Last year they admitted to having only 2 technicians, maximum experience 1 year, to service Jags and Land Rovers.

 

Are there no mobile diagnostic specialists in your area?

 

Good question.
But I have a sophisticated diagnosis system via the OBDII port.
Codes, live recording etc.
With no independents here in France, I'm stuck with the local Jag main dealer. Utterly incompetent.
Long story, but they had may car last year for 7 months trying to fix the P0171 leak I had diagnosed.
They replaced everything, and the site boss admitted that they had only 2 technicians, max one year experience, no diagnostics for my car, and towards the end they couldn't put back the "compressor" as they call it, so he said he had to bring in an old mate who showed fixed it.

And after 7 months the P0171, restricted performance, came back 100 miles later..
Coincidentally, the gear lever stuck in park, and they've now had my car again for 2.5 months, now saying that after replacing the part they have misfires on 2 cylinders when firing up (after 2 months sitting).
You couldn't make it up could you?
But I'm stuck with them - they have the car, with a fault and I can only wait for it to be fixed, and challenge any excessive bills, but which I will have to pay to get the car back.
I have taken advice, and here in France there is an excellent mediation process which I can use.
C'est la vie as they say here.
PS. In their favour I did get the loan of a 400bhp hybrid Ipace for the 7 months, nothing currently though.


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You are likely to reject this idea, but I urge you to verify that your battery is at full charge, and that it passes a “load test”, especially pertinent after the car has been unused for long periods of time. The battery is the crucial element as it powers all the electronic modules, and yes, restricted performance and misfiring can be caused by insufficient battery voltage.

 

Thanks SOV. I'll pass this to the Jag dealer.
They're so incompetent, probably never thought of this.
.

 

The number of times that a dealer’s mechanic has failed to consider battery condition/voltage as the cause of module misbehaviour is nothing short of alarming. Verifying the battery condition and connections is job #1 for modern car issues. Only after this verification should you consider proceeding to more involved procedures.

 

Is this reasonable?

Hello Mr Moore, I hope you are well. Thank you for your email, the technicians had already looked at the battery voltage. I think we have found the cause of the fault on your vehicle. It is indeed the fuel, there are deposits inside (see photos and video). We believe that these deposits come from a deterioration of the rubber fuel hoses due to age and fuel containing ethanol which has eaten away at the inside of the fuel hoses. We are obliged to check and repair the faulty elements on the entire fuel circuit from the pump in the tank to the injectors if you want your vehicle to work again. Do you want a quote for this operation?

 

I think it's time to find a different shop to work on your car. These cars are not some exotic marque that only a brand specialist can touch. For the most part, they are very similar mechanically to most other brands of that era. Many of the mechanical bits are straight from the Ford parts bin, reflecting the parentage at the time.

I'm also calling BS on the fuel line theory. Not saying it couldn't happen, but if it did, two very strong clues would be evident and EASILY confirmed:

1) Fuel pressure, read via live data on a scanner, would be low. This would show problems caused by lines swelling shut (but not necessarily shedding debris) and restricting fuel flow.

2) The fuel filter would have lots of rubbery debris inside. It's a simple matter to replace the fuel filter and cut open the old one for inspection. This would show problems caused by fuel lines breaking apart internally and shedding debris.

 

Low fuel pressure would set codes, but not the ones reported.

Find another garage!

 

Thanks for comment. You're right.
Unfortunately in this corner of France there are no other shops.
No independents.
So it's the Jag dealer or nothing.
And their possession is 9 points of the law, as my old dad used to say.
I have proof of their previous incompetence, but I can only pay up and maybe challenge via mediation.