Yea you can look at the flat spots on the cams, flat spots should be pointing at 12 in relation to the cylinder head, if one flat spot is turned more than the other, then yea you have one out of time.


I had one years ago where an independent shop tried doing secondary chain tensioners with no tools in place, and the exhaust cam on bank 2 was out. I had a lot of codes logged, more than what you have listed. Luckily this one was only 1 tooth out, so no damage was done. You'd know right away though if you were looking at the cams flat spots if one was out.


Just having a closer look at your picture of compression test. In a LH drive car ( USA ) Bank 1 is on the RH side if you're sitting in the driver seat, the passenger side of the engine. The codes you have say P0172 ( Running Rich Bank 1 ) P1074 ( Running Lean Bank 2 ). Cant say that I've come across those 2 codes alone like this before?? In your first post you said you had misfires on cylinders 1,4,5,6. The picture you posted says you now have misfire codes on cylinders 1,2,4. I take that 5 & 6 are ok now? 2 has popped up, 1&4 are still there??


You said you put new spark plugs in, are they the correct ones? and are they gapped correctly? This may not be the culprit, but better safe than sorry. Did you installed new genuine coils, not aftermarket? Did you recently fill the vehicle with fuel, maybe take a fuel sample just to rule out possible contamination? Has the fuel filter been changed? Even this late I've come across XJ ( 308 ) with the original style fuel filter, they were updated. Just some things to think about.


Also, I had many times on the 308's where the MAF has been an issue, but doesn't log a code for the sensor. It will log a code for something else. I have been able to take the MAF out and clean it, refit and check to see if it makes a difference. Other times I wasn't so lucky and to actually change the sensor.


Before you start diving into electrical issues, are you able to answer the questions I've asked 2 paragraphs up? What sort of mileage is on the car too?

 

For the codes, I cleared all codes Saturday, drove it about a mile, then pulled the codes again, and those are what are shown in the photo. My original codes were before I put in new NGK BKR5EIX-11 plugs (gaps checked) and coils. Coils are aftermarket but don't seem to have made much of a difference, especially with cylinders 1 & 4. I thought if they DID make a difference, then I would spring for new ones, but I hate to spend the cash until I know if that is the problem. Fuel and filter are a possibility, I'm down to about a quarter tank so I may drain it and change the filter if it doesn't look brand new. I cleaned the MAF a few days ago, so I don't believe that's the issue. The car has 179k miles so that doesn't help. Thanks for the suggestions.

 

If I was in your situation, I should buy a OBD2 connector and install the Torque (free) or Torque Pro (couple of $) app on your smartphone (that is if you have an Android, there are alternatives for an I Phone).

It might take a day to find your way in the app, but it will allow you to read several values of the engine emission process, and will probably give you an indication if the problem is shared over both banks, or more specific for 1 bank.
It will also allow you to read the values of the various sensors, and give you a direct indication of their working (like your MAF).

It will not give you the solution, but probably sufficient info to take the next right move.

 

Reread #21. With the cam cover off on the right side (bank one, cylinders 1 - 4), you need to turn the engine with the crank bolt and check the alignment of your cam flats (lots of threads on this subject and items in the stickies). Keep turning until A flat edge can be laid across the two flats to form a straight line. If you can't find such a spot, With your mileage and plastic secondary tensioners, you have probably jumped a sprocket and are out of time.

 

Thanks Eric, I'll look into that app.

Jim, re: #21, I checked the left side (photo below) and it looked good, the gap on the left edge was the same for both cams, although the photo doesn't show it exactly. I plan to try the right side tonight if I get home in time.

 

I saw the picture of the secondary chain tensioner, from what I can see it looks ok, the pad the chain rides on is still there. As for the recent photo of the cam with straight edge, that looks ok for that bank. Check the other bank, if its the same, then we can rule timing out.


The fuel filter is located on the left rear of the vehicle, above the axle. Look up and you'll see it, it wont be in the tank. It may be turning to an electrical issue at this stage, but need to rule out as much as we can.


You said the coils are aftermarket, just wondering if you swapped the ones from the misfiring cylinders to Bank 2 and see if the codes move to that Bank?? I've had new genuine coils be faulty out of the box, and aftermarket ones as well. Just something to verify and rule out.

 

Still following up on all the good suggestions, but my day job has slowed things up. I did pull the fuel injectors to test and clean them, and that was probably a mistake. The photo is a sample of the results. Plastic caps got stuck in the intake manifold on 4 of the injectors, and I had to use a screw extractor to get them out. Looks like new injectors are in my future.

 

Check eBay and the various fuel injection rebuild vendors. It's possible if not likely that you may find an inexpensive service kit that includes the O-rings, plastic tips, and filter baskets (if equipped).

Cheers,

Don

 

That's the plan. New injectors would cost more than I paid for the car!

 

There are companies such as FIC which are quite reasonable with their prices.

https://fuelinjectorconnection.com/

 

Misfire codes cross an entire bank of cylinders would have me looking at leaks between intake manifold and cylinder head, maybe a lazy O2 sensor.

 

For leaks, I sprayed everything with starting fluid to try and find one but didn't detect anything, although that isn't foolproof. I've been thinking about the O2 sensors, I have no idea if they are original, but had a BMW once that ran rough, and a cruddy O2 sensor was the cause. If the new injectors don't help, I may go there next.

 

Those injectors could definitely be the issue. They shouldn't come apart when removing them from the intake. Definitely start there. XJ 308's, even XK8 ( early X100 ) were prone to 02 sensors, 9 times out of 10, its the one that's the most PITA to get to, under the coolant resevior, then under the heatshield. Majority of the time you will get a code for this sensor, but have had some cases in the past that didn't, had to monitor them on datalogger to watch the signal. I hope the injectors fix the problem. Let us know what happens!

 

Well, I installed the new injectors and they made absolutely no noticeable difference at all, although the old ones were so bad, there had to be some improvement. So I took the car on a ten mile ride with the new injectors, new coils, and new plugs (glad I could contribute to the economy). It drove okay cruising back roads at about 40-45. But any time I started up a hill, the engine felt like it was losing power and "stumbling". While easing my way up the hill with very light throttle, all at once the Check Engine light would come on, the Restricted Performance message would come on, and the engine would begin running great! The lights went off after about 5 seconds, and it ran fine until the next hill, when it repeated the cycle. Got home and pulled the codes: P0301 (misfire A1), P0302 (misfire A2), P0304 (misfire A4), P0172 (A bank too rich, probably because of the misfires), P0174 (B bank too lean, maybe trying to compensate for A bank), and P1316 (excessive emissions). So my next step was to swap coils A2 and A3 to see if the misfire code would move. It didn't move but it cleared up A2, so now i have the misfire on A1 and A4. It's too rainy tonight to drive so I plan to clear the codes and take another 10 mile trip tomorrow and see what happens. More to come.

 

One thing to remember about rich/lean codes is that O2 sensors can only detect O2, not fuel, so you need to look at a "too rich" code more as a "too little oxygen" code. *Usually* misfire codes will result in the O2 sensor seeing a lot of oxygen due to improper combustion and, if anything, you'll see a corresponding too lean code.

The Jag has two sets of cats & O2 sensors and sequential injection, so you should not run into the scenario where one bank is affecting the other. It really should not happen.

Have you pulled values for the O2 sensors & fuel trims? I would look there. Normally I would also look at MAF & fuel pressure data, but since it's only affecting one bank that seems less likely.

Hate to throw this out into the universe, but do you have a service history on the timing chain? Also, maybe the VVT system? I don't know how that thing works or what codes might surface, but a cam out of phase could also result in this behavior. I've got an R, so no VVT to have had experience with.

 

For service history, I have a receipt where the tires were rotated about three years ago. That's it! I bought the car as a basket case so I didn't expect much, and that's what I got.

I took the car on another ten mile drive today (test loop through the country with no traffic). It did the same routine with not pulling hills until the CEL and Restricted Performance light came on, then it took off and ran great for about 30 seconds. If you've ever ridden a 2-stroke dirt bike where the plug starts to foul, and it almost dies, then suddenly the plug clears and it runs great, well that's how this feels.

My code scanner is again showing P0301, 0302, 0304, 0172, 0174 and 1316. Swapping coils did nothing for clearing 0302 although it disappeared for a day.

Any recommendations on a good bluetooth OBD scanner for real-time monitoring?

 

I use this one (only working for Android) and use Torque Pro on my phone, works like a charm.

 

I think I missed a reply: have you pulled the right side (bank 1, cylinders 1-4, codes 301, codes 302, 303, 304) cam cover and checked the timing of bank one cylinders?

 

The ELM327 is the obvious answer here, works with Torque and other OBDII phone/tablet apps.

Have you pulled the plugs after a clean + drive cycle to see what they look like? Are they doused in fuel? The proper plugs for the Jaguar won't put up with a lot of abuse, so if you had a problem, put in new plugs, continued to have the problem, and then FIXED the problem, the plugs could be fouled and still having issues.

The behavior on the road is weird, because there really isn't anything the car can tell about flat land vs. hilly land. On your test drives, are you just cruising down the freeway or are you really mashing on the throttle? If not, you should - it's important to know if it's really incline-based (unlikely) or load-based (really likely). If it's load based, that might suggest some sort of restriction... maybe a clogged cat, unresponsive MAF or O2 sensor or throttle position sensor?

 

Yes, I've pulled both sides and measured with a straight edge, the flat spots on all cams align.

As to the test drive performance, I'm cruising country roads at about 40 mph when the weird behavior occurs on the hills, and they're not really steep ones. I maintain a steady throttle, only increasing pressure enough to try and maintain the same speed. I definitely think it's load related. I haven't tried any WFO stuff because I'm still learning the engine.

Next step is to pull the new plugs and see what they show. I may also pull the O2 sensors because I've had those cause issues on older cars. But this lack of a misfire code on cylinder 3 is making me wonder if I have bad wiring to the coils on that side. I've seen that with Mercedes in the 1990s where the wiring disintegrated because of heat issues.