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I am helping my uncle out with his 2004 Jaguar XJ8. He has brought it to the dealership several times and they have replaced the battery, solenoid, all the way to the fuel pump but still has the issue.
Issue: The car will start and run but once it's shut off, it will not start until the next morning. It will crank over, all electronics work. He says it starts the next morning like nothing ever happened. Would drive a good 1hr into NYC no issue.
He said the dealership said it was the computer system and to replace the computer, they need to reconfigure the keys and no dealership has that, which i find hard to believe since he lives in NYC.
After some research I read about the Fuel Inertia switch could be a possibility, and to reset the pin and give it a try. Also mention of the crank position sensor. I will be looking into those when I visit.
So what I remember he said was replaced are the basics like battery, starter, solenoid, fuel pump, and injectors.
Can you guys point me to all the possibilities so I can check them when I visit.
Thanks
Last edited by GGG; 11-04-2017 at 04:07 AM.
Reason: Emphasise Model & Year
Not the inertia switch as then it would not start the next day without resetting the switch (you do it by hand).
Be certain about what was replaced. Find the receipts etc. Else something will fail to be replaced or done twice.
Check live data using OBD - especially sensors such as ECT. Especially when it won't start.
Either read up a bit so you can DIY it or find someone cheaper (and more useful) than the dealer. N.B. dealer = parts swapper. Often no brain required.
Does it really take until the next day, or would six hours work? I think the car is probably a X350, so it may be better to post there. I suspect it's a fuel system problem, possibly a vapor lock caused by a defective fuel pressure regulator, but I don't really know the X350 system.
I'm surprised dealers are having this much trouble diagnosing a no start condition that is so easily reproducible. It's sad that they've just seemingly shotgunned parts at it, but I guess that's what happens when pay techs a flat rate....They start losing money if they take the time necessary to do in-depth troubleshooting. All those parts you listed, except for possibly the fuel injectors, are relatively easy to check without replacing, if they would've just taken the time to do so.
You just have to start with the basics....Spark/Fuel/Compression/Air. First, get a cheap spark tester and check for spark. If you're getting spark that eliminates ignition related stuff and a lot of possible sensor issues. If that's okay, I'd also buy or borrow a fuel pressure test gauge and watch the fuel pressure. There are plenty of on-line tutorials on what your results mean.
I doubt you're having air/compression/exhaust related problems given the time frame you've described and assuming that the car runs fine (when it does run). Unless you have a bad clogged cat or something, but that will generally throw a code and cause the engine to run poorly.
Good luck!
Last edited by electechbw; 11-04-2017 at 11:03 AM.
Reason: clarity
I would think the dealership would simply start the car, let it run, then shut it off and when it wouldn't start again, "simply" go through all the basics to determine what is missing (Fuel-Air-Spark-Timing).
I like RJ's suggestion of fuel pressure regulation and vapor lock, though I don't recall hearing of this issue on an X350. It's late and my brain is tired so please forgive me for thinking out loud:
Vapor lock occurs when fuel pressure is lost suddenly, allowing liquid fuel to boil into vapor, which interrupts fuel pump operation in traditional systems with a return line from the fuel rail to the tank and prevents the engine from running until the fuel vapors have cooled and condensed back to the liquid state. The X350 has a "returnless" fuel system, without a return line from the fuel rail to the tank, so the fuel pump could not be trying to pump vapors unless the fuel level in the tank was low. But vaporized fuel in the rail is also a problem, because when the injector opens and a small amount of vapor enters the combustion chamber and is diluted with air, the resulting air-fuel ratio is so heavy on air that it will either not combust or will produce so little power that the pistons won't move.
The X350 doesn't have a traditional fuel pressure regulator (FPR) through which fuel passes, which can fail and allow pressure in the rail to drop suddenly when the fuel pump is shut off. Instead, it has a fuel injection pressure sensor or transducer (IP sensor) that measures the pressure in the rail and communicates this electronically to the engine control module (ECM). The IP sensor has a vacuum connection to the intake manifold, and I suppose that if the diaphragm in the sensor that is in contact with the fuel were to fail, then when the fuel pump was shut off the pressure in the fuel rail could dissipate through the vacuum hose into the intake manifold and allow the fuel to boil.
An FPR traditionally works in conjunction with a check valve or non-return valve that prevents fuel pressure from dissipating back into the fuel tank. The check valves are typically near the fuel filter or in the tank, often part of the fuel pump assembly. In the X350 the check valve is a dual design called the Parallel Pressure Relief Valve (PPRV). Here's what the Engine Management System manual has to say about the PPRV:
"Fuel is pumped from the fuel pump to the fuel rail via the parallel pressure relief valve and fuel filter. The PPRV contains two spring-loaded valves, which operate in opposite directions. The function of the valve is to:
1. Assist in engine starting by retaining a pre-set fuel pressure in the fuel delivery line and fuel rail whenever ignition is turned off, and hence the fuel pump is not energized.
2. Limit fuel-rail pressure due to temporary vapor increase in hot conditions while the ignition is off.
3. Prevent leakage from the tank in the event that the fuel delivery line is severed."
If the PPRV were to stick open in the side of the valve that is supposed to prevent fuel pressure in the delivery line from dissipating back into the tank, when the pump is shut off the resulting pressure drop could allow the fuel in the rail, already heated by the engine, to boil and cause vapor lock.
I've checked the Electronic Parts Catalog and don't find a separate illustration or part number for the PPRV, so it is probably built into the fuel pump module, so perhaps it has already been replaced on your uncle's car. Here's the diagram from the EMS manual:
I admit this is just a wild theory, but since it appears that the dealer service techs have been guessing, maybe a wild theory is worth considering. It would be easy to test this theory by connecting a fuel pressure gauge to the system to see if the pressure drops suddenly when the engine is shut off.
It would also help us think this problem through if you could post all diagnostic trouble codes the dealer technicians have scanned.
EDIT: I have confirmed that the PPRV is part of the fuel pump module and is not available separately, so if your uncle's fuel pump was replaced, so was the PPRV. This information is on page 84 of Jaguar publication 810-JAG, "Technical Training / Powertrain Systems / Engine Management and Diagnostics" (dated 06/2011).
I am helping my uncle out with his 2004 Jaguar XJ8.
He said the dealership said it was the computer system and to replace the computer, they need to reconfigure the keys and no dealership has that, which i find hard to believe since he lives in NYC.
I contacted a jaguar ecm specialist about my ecm . He stated the new computer would come loaded with all of the tunes. But it would be lacking the security which must be done with the computer in the car. He then suggested a locksmith and i thought it didnt make sense? The third locksmith called off a list of 10 said he could reset security to align key codes no problem for $150
A LOCKsmith .Amazing considering i live on a side of a mountain no where near a jag dealer or really many other jags locally
Thanks for helpful information everyone. I talked to my uncle and he said there are no check engine lights on for anything.
Sounds like checking the fuel pressure is first test. Also read spraying starter fluid in the throttle body when experiecing this issue to see if it will start would help determine if fuel is actually getting pumped in. Yes/no?
also will autozone have the right pressure tester for jaguara?
I have had starting issues with cars that have turned out to be crank sensor, the problem is that a crank sensor fault rarely throws a code, but what does happen is when the sensor starts to break down, it can cause starting issues, either from cold or from hot, there is no rhyme or reason, had a vauxhall that was a pig to start when cold, but would start first click of the key for the rest of the day, and had others that would start from cold first click, then were a pig to start when warm. just a though.
I have had starting issues with cars that have turned out to be crank sensor, the problem is that a crank sensor fault rarely throws a code, but what does happen is when the sensor starts to break down, it can cause starting issues, either from cold or from hot, there is no rhyme or reason, had a vauxhall that was a pig to start when cold, but would start first click of the key for the rest of the day, and had others that would start from cold first click, then were a pig to start when warm. just a though.
hi i had thought about the crank position sensor. Ive had that go on my ford ranger and it would not start at all so figure that if it was the CPS, the car wouldnt run at all. So sounds like it could be possible. Since you mentio ned it, i will give it a shot since it's only a 30-40$ part.
I have had starting issues with cars that have turned out to be crank sensor, the problem is that a crank sensor fault rarely throws a code, but what does happen is when the sensor starts to break down, it can cause starting issues, either from cold or from hot, there is no rhyme or reason, had a vauxhall that was a pig to start when cold, but would start first click of the key for the rest of the day, and had others that would start from cold first click, then were a pig to start when warm. just a though.
Hi Brian,
Your suspicion of the crankshaft position sensor (CKP or CKPS) is certainly valid on earlier models, but I am not certain whether this is as applicable to an X350. According to the Engine Management Systems (EMS) manual, at startup, the Denso 32-bit EMS relies on the camshaft position sensor (CMP) signals to identify the cylinders and establish correct ignition timing. From that point on, the engine control module (ECM) relies on the CKP for timing control.
Unlike the EMSs in earlier models, the Comprehensive Component Diagnostic Module of the Denso 32-bit EMS continuously monitors the CKP for a loss of signal or a signal that does not represent an expected reasonable engine speed for a normally operating engine, and for signal and/or ground circuit malfunction.
In the event of CPS circuit failure, the ECM references the Bank 1 CMP for cylinder synchronization, so the engine should continue to run, although the manual indicates that when a CPS fault is detected the ECM will reduce maximum engine speed.
That's what's supposed to happen, anyway!
See pages 102-105 of Book B of the EMS Manual available at these links:
I'm with you fully on that, but if the Jaguar technicians can't find a fault, there is clearly something amiss, but rather than try to figure it out logically, they just started throwing parts at it. I mean if I exhausted all avenues and got to the stage where I decided, I did have to start throwing parts, I would start at the cheaper end, and use some common sense and past experience and not chuck £1,000's at it.
I mean, they must have battery testers and chargers at a dealership, and yet the first thing they did was swap out a £200 battery that could easily have been tested, and probably had nothing wrong with it, then a solenoid and all the way up to a fuel pump, all these things are very expensive and easily tested.
A duff crank sensor is very possible and if that doesn't fix it, then you are back to square one and out just £40 and not £2000.
I mean, they must have battery testers and chargers at a dealership, and yet the first thing they did was swap out a £200 battery that could easily have been tested, and probably had nothing wrong with it, then a solenoid and all the way up to a fuel pump, all these things are very expensive and easily tested.
Since the OP is relaying information second-hand, we really do not know what diagnostics were performed at the dealership. Presumably the battery was tested prior to replacement, but if it was the original one, it was thirteen years old, so it's certainly possible the service department recommended replacing it just to rule out the vast number of undiagnosable issues Jaguars can exhibit due to a weak battery.
I agree that solenoids and fuel pumps are usually easily tested, but testing an X350 fuel pump for reliable operation may not be as easy as on earlier cars. You can't simply connect battery voltage to the pump to see if it runs. The pump is driven by the ECM, which sends a fixed-frequency 250 Hz PWM signal with a duty cycle that varies between 4% and 50% to control the fuel delivery rate. The REM receives this signal, doubles it, and applies it to the ground side of the pump to vary fuel pressure. Jaguar technicians (are supposed to) follow diagnostic procedures that ultimately get to the point where replacement of a component is indicated. Unless the OP can confirm otherwise, I think we have to give the technicians the benefit of the doubt that they followed the official Jaguar diagnostic procedure. It's certainly possible that the official procedure calls for replacement of the fuel pump, and if that doesn't solve the problem, replacement of the ECM (he was advised the car needed a new computer).
XJ8king: I am reminded that you did not tell us exactly which "solenoid" was replaced, and that you haven't posted the exact diagnostic trouble codes that were flagged. Note that many DTCs will not necessarily trigger the Check Engine Light, but may nevertheless help diagnose the root cause of the one-start-a-day issue. Can you please fill in these blanks?
Ah yes, but me being from the old school of mechanics, I call upon my considerable powers of deduction and my extensive tool kit, comprising a Hammer, a bigger hammer, an adjustable wrench and kept by for those special ocassions a sledgehammer. never failed me yet, LOL
11-03-2017, 04:42 PM
XJ8 starts ONCE a day. Always cranks over
