Hi Wayne, thanks for your input, much appreciated.

My point was that the Jag tech should have found the bent pin from the start and they should not have sold me a BPM, however I think they knew the real cause from the start or the first tech was incompetent, either way they ripped me off and gave me an RP parting gift.

The reason i brought up and am wanting to get a compatible ELM was not to resolve the loose pin/no start no crank issue, it is to now get an idea or starting point to solve the Restricted Performance issue the car now has.

Also am not sure if the BG-44k I purchased and poured into the tank was authentic or junk nor how to find out, no way to contact BG by phone.

So until I get an ELM, I still can't with certainty rule out the fuel side before moving on to the coils, plugs, sensors, catalytic issues, etc,

need to check fuel pressure even though i replaced fuel pump

there's the in line fuel filter which i tried to change but fuel keeps coming when I disconnect one of the filter connections even though I released the pressure at the valve, and I even tried to run the car and disconnect the fuel pump fuse while it was running til it stalled to purge out fuel from the line,

the MAF sensor, even though I cleaned it may be faulty

air intake possible issues even though I cleaned the throttle body,

there are so many possibilities and even one or more the Jag tech may have created that cannot be found with an OBD2, I don't know but what is for certain is that I have to get to the end of this story which has gotten old long ago. Tried hiring and tried fixing on my own, nothing gives.

Thanks alot,
Sid

 

Hi folks, the following is the latest update...

As was stated earlier the P0300 and P1316 were codes pulled by the dealership using their obd2 scanner.

I recently got my own scanner and pulled the codes again 3 times, meaning i ran the engine and even brought idle up to 2000 rpm for a while hoping BG-44k would help, then let it idle, pulled codes, noted them, then erased them from ECU, then shut off the engine each time, and the following is what came;

codes 1st time: P0300, P0307, P1314, P1316, P0357 and restricted performance message on screen.
noted them down, erased them from ECU, shut engine off waited awhile

codes 2nd time: P0300, P1316 no rp message, smoother/less stumble,
noted them down, erased them from ECU, shut engine off waited awhile

codes 3rd time: started engine no codes from obd2 except P1000 meaning nothing pending, no rp or any other message on dash screen, rpm to 2000 and engine running smoothly for about 5 minutes except I thought I was maybe hearing a very slight miss from the exhaust rythm but wasn't sure because it may have just been the catalytic working properly, then let it idle for a long time waiting for a potential code, all seemed like a miracle other than a very slight rough idle when I let the rpm lower to a fluctuating 647 to 655 rpm idle so after awhile I decided I might as well try to take it for a ride and see if it lasts, so I put the shifter in reverse to back out of the parking spot and as soon as I gave a slight peddle push to reverse, torque pro voice stated code P0308 and then P1316 , but no P0307 like during 1st code pull, so I put it in park and waited a couple of minutes then backed out and went for a test drive, car ran okay but stumbled a little so kept on driving a little while to see if it might be fuel related and hoping BG-44k may help, then went back to park it, waited awhile and no other codes came, so just shut it off.

I am not sure what to make of this at this point and I am wondering if when I reversed causing a sudden backward vehicle motion if something went or flowed in a forward motion at the coil/spark plug sector causing the P0307 code from the first code pull to change to a P0308 code at the last code pull, did I move something from coil 7 to coil 8?

Also, found it strange that Torque Pro didn't give me any fuel pressure and coolant temperature readings.

Any ideas about all this, before I open it up?

thanks alot,
Sid

 

The 7's mean cyl 7 and the codes say the coil is bad. Fit a new one, clear codes and see if OK.

Don't leave it longer than you must as it's busy damaging the cat conv.

 

Anyone know the Spark plug gap for 99 xk8 ?

I'm getting conflicting info... in the PDF at jagrepair.com it ranges from .035 to .051, and I am finding info at advance auto, autozone, and rockauto that the gap should be .052 .

Update:
NGK website says its .052 for the 99 XK8
Owners handbook says .050

Thanks

 

Hi, it said coil 7 on first code scan but then after erasing it, at the 3rd code scan it said coil 8 and didn't repeat coil 7 along with it.

So far I checked coil 8, looks pretty newish and clean but the spark plug looks quite dirty, and found a very little bit of oil at the bottom where the plug sits at top the engine threading so cleaned the area then purchased a new set of plugs.

Thanks alot

 

The following is what it says at Gus's websites PDF on Page 22 chart 18;

http://www.jagrepair.com/images/Auto...sb_09_2003.pdf


Thanks

 

"NGK doesn't recommend adjusting the spark plug gap < or > .008". The reason for this is the ground electrode and center electrode won't line up properly, hindering spark plug performance."

 

Causes of Carbon Fouling:

• Continuous low speed driving and/or short trips
  
• Spark plug heat range too cold
• Air-fuel mixture too rich
• Reduced compression and oil usage due to worn piston rings / cylinder walls
• Over-retarded ignition timing
• Ignition system deterioration

Pre-delivery fouling

Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.



Causes of Overheating:

• Spark plug heat range too hot
• Insufficient tightening torque and/or no gasket
• Over-advanced ignition timing
• Fuel octane rating too low (knock is present)
• Excessively lean air-fuel mixture
• Excessive combustion chamber deposits
• Continuous driving under excessively heavy load
• Insufficient engine cooling or lubrication

The most serious result of selecting a heat range that is too hot is overheating. Overheating will cause the electrodes to wear quickly and can lead to pre-ignition. Pre-ignition occurs when the air-fuel mixture is ignited by a hot object/area in the combustion chamber before the timed spark event occurs. When the spark plug firing end (tip) temperature exceeds 800°C, pre-ignition originating from the overheated insulator ceramic can occur. Pre-ignition will dramatically raise the cylinder temperature and pressure and can cause serious and expensive engine damage. When inspecting a spark plug that has experienced overheating or pre-ignition, blistering on the ceramic insulator and/or melted electrodes can sometimes be found.

As a general guideline, among identical spark plug types, the difference in tip temperature from one heat range to the next is approximately 70°C to 100°C.


FUEL

When using an ethanol blend fuel with high ethanol content in high performance applications, a colder heat range may be necessary. The spark timing can be advanced further because ethanol blend fuel has a higher resistance to knock (higher octane). Due to the decreased knock, there will be less audible “warning” from knock before the spark plug overheats and pre-ignites.

Some types of fuel additives in lower quality fuels can cause spark plug deposits that can lead to misfires, pre-ignition, etc.

 

Misfires

• A misfire occurs when the spark travels the path of least resistance instead of jumping across the gap. Misfires can be caused by the following:
  
  1. Carbon fouling
  2. Worn or deteriorated ignition system components
  3. Too large of gap size. An incorrect plug gap for your engine can contribute to a high rate of misfires, loss of power, plug fouling, poor fuel economy, and accelerated plug wear.
  4. Spark timing excessively advanced or retarded
  5. Damaged spark plugs (cracked insulator, melted electrodes, etc)
  6. Mismatched ignition system components (plug resistance / wire resistance, ignition coils / igniter modules, etc.)
  7. Insufficient coil primary and/or secondary voltage – voltage required to jump the spark plug gap higher than coil output

 

Resistor spark plugs use a 5k ohm ceramic resistor in the spark plug to suppress ignition noise generated during sparking.
It is strongly recommended using resistor spark plugs in any vehicle that uses on-board computer systems to monitor or control engine performance. This is because resistor spark plugs reduce electromagnetic interference with on-board electronics.

They are also recommended on any vehicle that has other on-board electronic systems such as engine-management computers, two-way radios, GPS systems, depth finders or whenever recommended by the manufacturer.

In fact, using a non-resistor plug in certain applications can actually cause the engine to suffer undesirable side effects such as an erratic idle, high-rpm misfire, engine run-on, power drop off at certain rpm levels and abnormal combustion.

 

Since you mentioned it, Oil in the plug well means the Well seals are going, These will need to be replaced, they are between the valve cover and cam. You will need those oring and I'd suspect valve cover gaskets.

 

Is that a complicated task, and are the well seals and valve cover gaskets dealer only parts?

Also, I didn't get to the other cylinders yet but in this one there was very little oil, maybe 5-7 drops worth. Is there an additive or something that may help?

Update, i checked online well seals but can only find "Spark Plug Seal" and "Spark plug boss to cam cover "


Thanks alot,
Sid

 

On a 99 car you should have the AJ27 engine(vvt connections on top of the valve covers is the quick way to identify the AJ27). The Felpro part number is in the stickies somewhere - from memory it's VS50724 - much cheaper than the Jaguar one. Fairly easy job to change - just be sure to torque the covers correctly - they're plastic and easily cracked/warped by overtightening.

 

sorry but what is vvt?

I just googled and that part number is for valve cover gaskets. jamdmyers said i also have to replace the well seals?


Thanks alot

 

Okay I found a picture for spark plug boss seals on this page https://www.jaguarforums.com/forum/x...-plugs-135516/

Thanks

 

The plug seals are part of the set.

 

ok heres aswitch 99 xj8 117k on the dial codes pop P0300 no OTHER codes drives but needs to be in nuetral and foot on gas to stay running ---- thoughts new plugs fuel injectors ok

 

Your post is very hard to read, and you should start a new thread rather than hijacking an existing one.

There are many possible causes, but first I would clean the throttle body throat and butterfly with a rag soaked in cleaner. Not by spraying cleaner in the throttle body.

Please visit the new member area and introduce yourself:

New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

 

Same problem, slightly different codes. While driving home in the rain yesterday, I got intermittent Restricted Performance warnings on the dash which went away after a few seconds.

Driving home tonight in the mostly dry, I got the RS warning from a stop. This lasted the few remaining blocks and manifests as a nasty miss when revving the engine in the drive.

Went out just now, 15 minutes later, and started the car with the code reader attached. No problems at all, but there is a stored code, P0354, coil D primary/secondary circuit.

So open channel D Mr. Solo. Is the ignition system susceptible to water problems? This is a new one for me.

P.S. Look at the ingredient list on that BG44 can. It's about 48% mineral spirits, 48% Naphthalene, and 4% secret sauce. Save some money: Mix it yourself with ingredients from the hardware store. Jonesing for the 4% secret sauce? Add 4% nitromethane from the race gas store. It's not enough to actually do anything, but it makes your exhaust smell great!

 

Hi Billll, have you tried erasing the code to check if it comes back?

Sid