Jaguar S-Type 3.0 2003
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You've got to realize you have an unusual situation and are in somewhat uncharted territory here. It's not as if any of us are experts or have seen this before. We can't conclusively state, "This sounds like a defective XYZ sensor" or anything like that. You may just have to make some educated guesses and try a few different things.
Personally, I'm big on reviewing the history of when the problem started. Unless I've missed something, I'm still unsure if the rough running got better or worse after all that recent work.
One thought is to use a mechanical gauge to check the fuel pressure. The computer adjusts the fuel pump output to maintain a certain pressure range. Fuel scheduling assumes a certain pressure is present. If the pressure sensor is inaccurate, the computer will happily adjust pump output to this invalid signal. The end result is too much or too little fuel, with no fault codes.
Personally, I'm big on reviewing the history of when the problem started. Unless I've missed something, I'm still unsure if the rough running got better or worse after all that recent work.
One thought is to use a mechanical gauge to check the fuel pressure. The computer adjusts the fuel pump output to maintain a certain pressure range. Fuel scheduling assumes a certain pressure is present. If the pressure sensor is inaccurate, the computer will happily adjust pump output to this invalid signal. The end result is too much or too little fuel, with no fault codes.
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You're saying the car sat for two years? These cars are notorious for fuel pump problems after sitting idle for extended periods. I'm not saying to rush out and replace the pump, but certainly check it out.
How much have you driven the car since bringing it out of storage? Is it still running on the same old fuel in the tank from storage?
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Definitely check the pump output with a mechanical gauge and compare it to the scanner value that the computer sees. There are no guarantees the new pump is good, or is receiving a correct command.
Where are you located? Even if the fuel is fresh, could quality be a problem? These engines require high octane fuel. If the fuel quality and/or octane is low, preignition may result. But in that case, the knock sensors may be doing their job and retarding the timing to prevent engine damage. This could easily cause low power under full throttle, but with no fault codes.
Where are you located? Even if the fuel is fresh, could quality be a problem? These engines require high octane fuel. If the fuel quality and/or octane is low, preignition may result. But in that case, the knock sensors may be doing their job and retarding the timing to prevent engine damage. This could easily cause low power under full throttle, but with no fault codes.
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Another thought about fuel pressure. Set up your scanner to show live data. Have a helper watch the scanner while you drive on an empty road and floor the gas pedal. IIRC, the fuel pressure is supposed to rise with increased load on the engine. If the pressure stays the same, that points to the computer not receiving a proper input (fuel pressure regulator?). If the pressure drops, that's probably a physical fuel delivery problem, such as a marginal pump or a clogged pickup sock. Won't cost anything to check...
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You don't have a CKP sensor fault. CKP sensor is the generic definition of code P1245, applicable to most vehicle brands.
For Jaguar, however, this code translates to "Engine crank signal low voltage". You've got to be real careful to always follow the Jaguar definition of a code, not the generic definition your scanner may be telling you.
Details here:
http://jagrepair.com/images/AutoRepa..._OBD_II_R2.pdf
If P1245 hasn't returned, it was probably just a nuisance thing. I'd only worry about it if it keeps returning.
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