This is the coil and the scratches. This is from when I replaced the spark plugs last time. I believe it has not changed since then, so maybe now is not moving that much.

There is something going on there. There was a previous attempt to glue the insert by somebody, but I think the insert is galled since the bolt does not turn freely inside it, which makes the insert dislodge, even when you reach target torque, the insert is pushed upwards.

Inserts are an unknown science to me, can I just replace it with any aftermarket one with similar size? At least I want to have one that is not galled.

If I do the back pressure test, and the fuel pressure regulator test, and I find nothing, this is going to be definetely something I'm going to be looking at.

 

i used jb weld to fix mine in place, after widening the well a bit to accommodate the glue and of course blanking insert bottom, it holds well, i don't see the reason why you couldn't use any aftermarket stuff there

 

Reread your posts: I am beginning to think you have a timing problem — just because your secondary tensioners were updated doesn’t mean he did it right. Pull the plugs again, pull the cam covers and check the timing (straight edge across flats).

that rub on the coil should make no difference.

 

I second that, definitely worth checking

 

I close the last coil cover tomorrow, I had to replace one spark plug that was damaged., don't know why, my theory is that I was not careful enough when dismounting with engine hot before compression test.

2nd hand FPR received, I hope I can test tomorrow. This the type with the long support bracket, I don't have torque data, in the manual it is stated 10 NM for the bolts attaching to the fuel rail, but that is a different FPR.

If no conclusion, then vacuum test.

If not I think I'll be taking some car holidays, knowing that replacing a bolt takes me two weeks, I need to be ready for technical inspection in December. I can't risk removing cam covers. I'll focus on adding injector cleaning and repairing that coil insert that is giving me suspicions.

But if we get there and I open the cam covers, should I replace all joints (they have 400 km on them) I guess. Then I need a wrench to turn the engine right?

Thanks

 

You can turn engine by hand no need for wrench, make sure you turn it in the right direction to not damage anything
Don't worry about the gaskets, 400km is an absolute nothing, i would just reuse them
Just tighten fpr enough and it will be fine, it is torque dependent application

 

It is torque dependent or not torque dependent, sorry it was not clear.

Car is back on the road after compression test, everything ok.

Mission to replace FPR aborted, I need a fuel extraction tool and the upper bolt of the FPR is going to be impossible to torque tighten with what I have. For the lower one I think I can, I did a position test with the tool.

By the way @xjack just realized I have that very same brown cristals you were talking about in the union of the coolant crossover to the passenger side intake to the engine, the cristals looks veeeery old. My car has a small leak in the lower radiator area, other than that absolutely no issue to keep coolant temperature or with the heating system. But that is for another thread once I finish with this.

 

Ehhh no, just a typo, it is not important as long as you don't brake a bolt tightening or leave it too loose to hold fpr
I had a look around and i didn't spot them anywhere else those crystals exist only in this particular place so it must have something to do with the temperatures there and probably neglecting coolant changes

 

Just got myself a torque wrench for spanner inserts and some fuel extraction kit. Back in action in some days.

Definitely what is hindering me the most is being forced to stop every 5 minutes because of needing some new tool or product. I want to believe I'm already pretty well sorted but they keep coming.

 

FPR replaced. It was hard putting back again those bolts to put it that way. There are no words, imagine putting the bolt back in with a thread attached to it in case it falls. The very difficult one is the one in the support bracket, the cable harness is on the way. At the end I could only torque one of the three, the other two are "tight enough".

The only difference I notice is that the vibration I feel (coming from the engine I believe, on my seat) at idle is much more dampened, at times it disappears. The car seemed to lose power arriving at 4k rpm at WOT rather than just hitting a wall, but it was a short test.

Next objective is to do a vacuum test to see if I can cross from the list clogged cats.

Overall the car drives better and better, I want to put some kilometers on it after the vacuum test, then I guess I'll have three options: timing (can a jumped teeth produce nominal compression values?), cleaning injectors or fuel pump.

 

I usually stack paper towels to prevent things falling in a wrong places, but little extendable magnetic pick up toll works a charm for all the rest
I doubt it jumped the teeth, symptoms would be much more severe, but badly set timing is a real possibility

 

By the way while I was waiting for the tools to arrive, I put some silicon spray on the oil cap and fuel cap. Now I wonder if the less vibrations I feel has to do with the oil or fuel cap sitting tighter.

I should in principle not have any vacuum leak, my LTFT are around 3 for both banks when car is hot.

Final thought, I also saw in another thread a gentleman with an XK8 who had the same issue as me, it ended up being the MAF!!

 

Not sure if it would work but you could try running engine with maf disconnected, it will throw errors but you will know if it lets you rev above usual

 

You are being too careful: pull the coils; pull the cam covers (don't overtighten, reuse the gaskets and inserts); turn the engine (note the direction it moves when it runs, turn it in that direction with a spanner); see if the flats line up as shown in all the threads on changing secondary tensioners.

 

absolutely, it is two hours job at most easy and gets you to know your engine, pure joy

 

Yep, I put a long hose on my gauge and have it in my lap whilst driving.

 

This weekend I plugged a vacuum gauge to the engine.

Engine warm and at idle, needle is solid at around 16 inHg. If I rev it a couple of times, it then stabilizes at the border of 17 inHg (being a healthy engine between 17 and 22 inHg). So I am slightly below or at the border.
I read this could mean different issues, like clogged exhausts, maybe a minor vacuum leak, timing off or worn piston rings.

I revved it and kept at 2500-2600 rpm for some good 30 s and needle raised to 20 inHg, kept steady. Flickering the gas makes the needle go all the way dow to zero or almost and quickly back to its nominal value after an overshoot.

So, from my basic understanding, there are no clogged exhausts.

At this point, I have finished my basic troubleshooting. For future users, this is a summary of what was done:

- MAF cleaned. Idle value makes sense and values go as high as 170 g/s before encountering my issue, which is a normal value for the power the car delivers at that moment.
- Air filter was replaced by mechanic.
- Throttle plate cleaned (with dry rag). Throttle opens to the full range without apparent issues.
- Trim values seem ok, LTFT is around 3-5%
- Fuel filter was replaced by the mechanic, and is placed in the correct sense.
- Fuel lines were visually inspected, although not thoroughly, the part attaching to the tank seem in good order and not kinked.
- Compression was tested engine dry wand warm, all cylinders between 145-150 psi.
- Fuel pressure was tested with unclear results: one test delivered 2.6 bar in static and another 2.8. The mano did not react to the engine revving and later delivered weird results.
- Because of this, FPR was replaced by a 2nd hand (normally functional), without the behavior of the car changing.
- Spark plugs were replaced since the ones installed by mechanic had a lower gap than nominal.
- Secondary tensioners were replaced by mechanic.
- No OBD codes thrown.
- Issues happens at any gear, so even if the issue sometimes seem like a kick in the butt, I discard gearbox. Other than that gearbox behaves flawless.

So, I think I have the following paths to take:

- Discard a vacuum leak, smoke test.
- Check timing, as you have suggested.
- Inspect fuel pump/replace.
- Clean injectors
- Maybe try a MAF? Try a new oil cap, since I sometimes hear a slight whistle, and tampering with it seems to affect a vibration I feel on my butt at idle.

So yes, I'll be checking the timing, but not just yet. I need some time off the car.

 

Checking fuel pressure, even with the gauge hanging out of the window, is a piece of cake compared to replacing the pump, keep that in mind
Cleaning injectors won't do any harm but may help
Instead of new cap, just replace orings on both cap and dipstick

 

especially the dipstick

 

Oh GOSH!!!!

I just opened up a new thread with the SAME Issue with my car!!!

It stops at 4-4200 RPM when allerating and when it's quite hot engine dies...(!)
I also recorded the videos for anyone to see

here's the thread with both VIDEOS = Jaguar XJ8 3.2 - Engine doesn't go over 4200 RPM cold - engine dies when HOT [VIDEOs] - Jaguar Forums - Jaguar Enthusiasts Forum

SO I'm following this with MUCH attention...