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You did not write about the big picture. Was that car a daily runner or was it sitting for a while?
Any chance that your problem is old petrol (sometime it takes only 3 month for petrol to get bad). My van does not care about old petrol much (it has a carburettor), but highly tuned fuel injected Jaguars are quite susceptible to failure due to old petrol.
You did not write about the big picture. Was that car a daily runner or was it sitting for a while?
Any chance that your problem is old petrol (sometime it takes only 3 month for petrol to get bad). My van does not care about old petrol much (it has a carburettor), but highly tuned fuel injected Jaguars are quite susceptible to failure due to old petrol.
My apologies,
It is my daily driver
It had just undergone a full engine rebuild, along with a supercharger porting and rebuild from Powerhouse.(4 months ago)
When I had first put the engine back together with the new supercharger, it ran like a dream but a month later it started to hesitate after 5 pounds of boost and misfire at idle, which only got worse as the car got to operating temperature.
The only thing fuel related I’ve noticed recently is the fuel injector wiring was shaved down to wire by the charge air coolers but it’s not touching other metal/wires.
I’ve never heard of previous owner replacing fuel filters or pumps so it may just be their time to go but I’d like to confirm before doing all that.
A thought: Since this seems to be a late arriving issue, I would look to weather: cold weather. Check the temperature sensor reading on the OBD. A stuck sensor in the water pipe will cause an enrichment for starting or a too lean for a hot car condition: much like choke issues in the last century.
I don't know where that sensor is on SC vehicles; it is in the cross-over pipe on regular XJ8s. But live data on the OBD will show the condition.
There would be 2 temp sensors for engine regulation , the coolant temp sensor which has a value that has the engine regulation enter closed loop
Inlet air temp sensor which has lesser effect ( fine mixture adjustment ) then the one putting it into closed loop
You can read a value with a meter when the coolant should be hot enough which brings about the coolant thermostat which may not let coolant get hot enough
See page 129 and back on 34 for calibration charts
>> The only thing fuel related I’ve noticed recently is the fuel injector wiring was shaved down to wire by the charge air coolers but it’s not touching other metal/wires.
If one section of wire is damaged, it might be worth looking for other sections, plus, the damaged section needs to be wrapped with insulation tape.
>> I’ve never heard of previous owner replacing fuel filters or pumps so it may just be their time to go but I’d like to confirm before doing all that.
Replacing an old fuel filter is always a good approach.
First of all, it helps others to help you if you tell us the year and model of your Jaguar. I had to go to your Public Profile to see that it is a 1998 XJR. These details are critical for supplying the most accurate replies. If you will visit your User Control Panel you can Edit your Signature to add the year, model and engine details so they show up in every one of your posts.
The most alarming thing you've reported is that "The only thing fuel related I’ve noticed recently is the fuel injector wiring was shaved down to wire by the charge air coolers but it’s not touching other metal/wires." You really ought to thoroughly repair all damaged wiring. The fuel injector ground wires connect directly to the ECM, so bad things could happen if the wrong wires short.
Here are the definitions and published possible causes of the codes you scanned from the 1998 DTC Summaries, which I am attaching.
The P0507 certainly suggests a significant air leak. Regarding the use of a smoke machine, I don't know how experienced you are, but the first thing to know is that some of the less-expensive machines are regulated to 1 psi output for safe use in testing EVAP systems. To test the air intake on your car, 10 psi or even higher may be necessary to find certain leaks.
Also, you don't ever want the smoke to come into contact with the wire in the MAFS because it will be permanently contaminated by the burning oil. Also, you need to inject pressurized smoke into every access point you can, not just the main air intake pipe (with the throttle butterfly plate propped open with something safe like a plastic trim tool). Inject into both ends of the breather pipe with the other end still connected, inject into the oil filler neck, the brake booster pipe, the oil dipstick tube, etc. Another tip is that anywhere you can see oil leaking out, unmetered air can be inhaled when the engine is running. So check your camshaft cover gaskets, oil filler cap, breather pipe connectors, etc.
P1238 suggests the cruise control Vacuum Switching/Solenoid Valve 3 (a.k.a. Solenoid Vacuum Valve) is disconnected or there is a problem with its wiring. Probably nothing to do with your engine performance unless the vacuum hose is detached, constituting a leak.
First of all, it helps others to help you if you tell us the year and model of your Jaguar. I had to go to your Public Profile to see that it is a 1998 XJR. These details are critical for supplying the most accurate replies. If you will visit your User Control Panel you can Edit your Signature to add the year, model and engine details so they show up in every one of your posts.
Thank you I’ve been trying to figure out how to do that.
The most alarming thing you've reported is that "The only thing fuel related I’ve noticed recently is the fuel injector wiring was shaved down to wire by the charge air coolers but it’s not touching other metal/wires." You really ought to thoroughly repair all damaged wiring. The fuel injector ground wires connect directly to the ECM, so bad things could happen if the wrong wires short.
I was unaware it went straight to ECU. I’ll definitely have to to a more thorough repair then.
Also, you don't ever want the smoke to come into contact with the wire in the MAFS because it will be permanently contaminated by the burning oil. Also, you need to inject pressurized smoke into every access point you can, not just the main air intake pipe (with the throttle butterfly plate propped open with something safe like a plastic trim tool). Inject into both ends of the breather pipe with the other end still connected, inject into the oil filler neck, the brake booster pipe, the oil dipstick tube, etc. Another tip is that anywhere you can see oil leaking out, unmetered air can be inhaled when the engine is running. So check your camshaft cover gaskets, oil filler cap, breather pipe connectors, etc.
Sadly this was my first ever time trying out the smoke machine and even sadder, the smoke most likely DID touch the MAFS wire, I noticed the car now seems to run even worse since I did the smoke leak test.
I’ll also use the locations you advised when I try again.
As for the gaskets, I believe I have a rear main seal that is blown, could this cause the unmetered air as you suggested? That was a new problem AFTER I rebuilt the engine/supercharger.
P1238 suggests the cruise control Vacuum Switching/Solenoid Valve 3 (a.k.a. Solenoid Vacuum Valve) is disconnected or there is a problem with its wiring. Probably nothing to do with your engine performance unless the vacuum hose is detached, constituting a leak.
I just went and fixed all of those t fittings with new ones so hopefully isn’t that but I’ll definitely have to double check.
Cheers,
Don
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I forgot to mention this, It doesn’t misfire at all in park, in fact it runs perfect. But in drive is when it starts to misfire.
Although it only happens after the car gets to operating temperature. On a cold start the car has no misfires and runs great but just gets worse as the car heats up.
As JHartz mentioned weather, I live in SWFL and during peak day the car runs significantly worse, IAT is 140F at Idle.
But come night time or on a cold start the car runs way better with less misfires and can power past 5lbs of boost without hesitating as bad.(never checked IAT at night)
To add on about the rear main seal area, I noticed a small amount of red fluid along with the oil. I believe it’s the power steering fluid, but my question is, could my transmission be causing this?
As for the responses on fuel pressure, I have yet to get my reader to see if it can show me that or if I need a tool for it.
Ill try and get that done tonight and put up another post.
Don B. just gave me my x-mas present:
> Also, you don't ever want the smoke to come into contact with the wire in the MAFS because it will be permanently contaminated by the burning oil.
I did not know that. I will certainly make a mental note for my future endeavours there..
I’ve noticed that if i put the car in run and let it get everything going for 15-30 seconds before actually cranking it over it doesn’t surge and runs pretty good until it get to temperature.
But if I leave it overnight and immediately start it, it will tend to surge and hold a high RPM at idle around 1200-1500 and will hold 30MPH without throttle.
One likely cause of the Cylinder 6 misfire is that the ignition coil is malfunctioning when it gets hot. A quick test would be to remove the 6 coil and swap it with another cylinder, ideally one that is not located right next to Cylinder 6, such as Cylinder 2. Clear the codes, run the engine and see if the misfire code moves to Cylinder 2. If so, you've confirmed the coil is bad.
Another possibility is that you still have unrepaired fuel injector wiring that malfunctining when it warms up.
While you have the coils removed, check for oil around the spark plugs. Oil from leaking spark plug tube seals can lead to misfires because the oil seeps down the spark plug threads and forms an insulating layer that interrupts the spark ground path via the plug threads to the cylinder head and engine ground strap.
Here's the cylinder numbering diagram. Your scan tool may be using the post 2002.5 model year numbering system:
Your STFTs look great at just +1.6% and +2.3%
At +7.0%, the Bank 2 LTFT is a little high, consistent with the P0507 code you reported earlier.
At +14.1%, the Bank 1 LTFT indicates significantly lean running in that bank, so there may be an unmetered air leak that affects Bank 1 more than Bank 2.
The transmission ECM and the engine ECM do definitely regulate each other as they dance together though all ranges
So ......................maybe connector clean of both ECMs connectors including the connection on the transmission body itself
The X300 transmission body connector is tricky to get off correctly and not destroy and maybe similar to the X308 transmission
There was someone on a similar X300 that had an ajar / loose transmission ECM connector and many others the X300 trans body connector dirty causing engine regulation issues at speed range after coming out of park detent
Finally was able to get a fuel gauge on it and results are not good.
Firstly the car will go into Restricted Performance intermittently seemingly out of nowhere. And when it is in restricted performance mode,when I start the car up OR when I shift from P to D or R the RPMs drop to 400 before settling around 600.
I also replaced the fuel filter when I cleared the codes and the car ran great for the first day but the second day the codes came back and ran even worse than before but I haven’t cleared the codes again since.
Now the car will misfire at anytime when it used to only misfire at Idle or after 5 pounds of boost.
I had the ignition in run and it was only showing 19PSI when I cranked it over it was only at 21PSI( I cranked it only for 2 seconds because I’ve got coolant and vacuum lines disconnected to get the gauge on.)
I also switched the coil pack on Cylinder 6, cleared codes and it still came back on the same cylinder. Could this be both injectors and fuel pumps going bad?
The PSI is also slowly going down
Fuel or air problem?
