Use the fuel proof O - rings starting with the letter V

With the key in run there should be 12 V present / sitting on the injector connectors

The 6 power / power sitting wires will have the same color ( Black / Light Green ), the timed ground wires ( 6 ) will have different colors

The rear 2 coil connectors can be mixed / crossed and the wire colors are

Plug 5 Black / Orange

Plug 6 Black / Purple

 

Viton

 

Been a bit... I was waiting for the O-rings forever, then got the flu. But I also got myself a nice battery charger/tender so I could stop borrowing one. I have >finally< gotten the car to start. Anybody had "a bit of corrosion on the tips of the coil packs" on their bingo card? I scuffed up the tip of each coil pack rod/spring with sandpaper after discovering some had weak or spotty continuity. That and the new battery charger were the only changes, and now it starts! Runs terrible though, but I'm hoping that's just because I poured a bit of oil in each cylinder for fear of bore wash. They were brand new so I will try to clean them, or just order more if that doesn't work.

 

Notice the widening gap and high heat range for your supercharged

Which spark plugs should I use for XJ6 X300? - Jaguar Forums - Jaguar Enthusiasts Forum

 

>Resolved<, sort of. Issue for me was fixed by lightly sanding the coil pack tips/rods, and/or putting the car on a good trickle charger. I just tried it out after changing the plugs and fixing the vacuum leak, and its running better.

However, the idle is a bit rough and low, the car will not go over 1000 rpm, and my catalytic converter was glowing red when I shut the car off and popped the hood. My first thought is that I've mixed up two of my coil packs, but they really only fit one way. The wires aren't long enough to swap 2 over. I'm confused yet again.

 

Progress!

The ignition coils that are easy to switch are No. 5 and No. 6, so double check those.

Another common problem is that the insulation on the wiring to the ignition coils becomes brittle and flakes off, allowing the bare conductors to short. If you don't see any signs of this along the top of the engine, check the wiring at the rear of the engine where the harness bends. This problem often manifests itself after the harness is disturbed to remove the coils.

Cheers,

Don

 

I tried a handful of things but nothing worked. Swapped coils #5 and #6, that made it worse. Unplugged each coil individually as the car was running, the engine developed a clear misfire as I unplugged each one. Found the cruise control paddle had been flipped on, turned that off. Tried unplugging the top 2 O2 sensors, no change.

Just to be a bit more descriptive, the car will start right up now. It idles at 500-800 rpm but its rather rough at 500. When I press the gas I can get 1000 rpm but it feels like there's a rev limiter? It will stutter up about 100rpm at a time to maybe 1300-1400 and then bog down. When taking my foot off the throttle the rpm drop way down and sometimes stalls.

 

My first guess would be an intake air or vacuum leak. Were any vacuum hoses or crankcase breather hoses disturbed? There's a breather hose that connects at the middle left edge of the camshaft cover.

 

I don't think it is but I'm out of ideas. I had previously gone through the whole intake and refreshed every gasket and O-ring in it. I actually just replaced the cam cover with a much nicer one from the junkyard this past week. Went there looking for crankshaft sensor, cam sensor... found a clean cam cover.

I had also replaced all 4 O2 sensors while the car was sitting and now I'm wondering if that could contribute? I would have thought the car would just stay in open loop if it was running this badly.

 

The O2 connectors can be swapped

The O2 connectors on the car side have 3 wires the same color , the 4th wire different , this determines position

Blue / cylinder 1 , 2 , 3

Red / cylinder 4 , 5 , 6

The Aft 2 sensors only are used for closed loop engine regulation only after the car warms to 88 C coolant temp

 

Great find on the cam cover! So any chance the crankcase breather hose cracked somewhere while you were swapping in the new cover? Those hoses tend to become brittle with age.

 

Small update... there's no vacuum leaks up top. Breather hose seems fine, the accordion tube is fine, its new. Tube from supercharger to intercooler is also fine. Everything else I'd have to check from underneath.

I tried changing my spark plugs from NGK to the Champion RC12YC, but that didn't help. The NGK's were new but are already very black and sooty. Seems like the car is trying to run absurdly rich? Can the fuel pressure regulator fail and let too much pressure into the rail?

 

Yes, when the diaphragm in the FPR fails, raw unmetered fuel is inhaled directly into the intake manifold. One easy check is to pull the vacuum hose off of the FPR, crank the engine, then look at the vacuum fitting on the FPR. If you see any wet fuel, the diaphragm has failed.

 

Exhaust leaks ?

If they leak they will let unconsumed O2 to the sensors at idle and they will respond to enrich the mixture to consume the biased reading

Loose donut gaskets , crack at the Y pipe ?

 

Tonight I did a pressure test of the intake, now I'm certain there are no vacuum leaks. Plugged the intake with a glove, blew into the "PCV" hose until the glove was about ready to explode. No whistles, no leaks. I will check the exhaust next. Compared to my X-Type the exhaust is a breeze, haha.

 

The exhaust donut gasket studs can only be got from underneath.

!3 mm on a long extension and universal , may be 15 mm

One is too close to a pipe for the universal so I used a loose fitted ( coupled / attached ) socket to extension square to get 15 degrees

 

A smoke test is more conclusive, but every part of the intake system and crankcase breather system has to be tested, usually at a higher pressure than a rubber glove can withstand.

 

Whoo boy that was a workout. Started by trying to undo the manifolds at the cats but those nuts are really rusted and rounded; it was going badly. Then I noticed the slip joint right there, so I got my big wrench and sheared the nut off it, then hammered it until it came loose. Lifted the whole assembly out the top despite significant troubles. There is at least one massive exhaust leak at the rear of the engine. Also going to have a look at the cats and those center joints, they seem loose.

 

When putting it back together the 2 manifold casings have to go on first then the pipes from the bottom ( no clearance for whole thing )

When you bring the pipes up from underneath be careful to not damage the donut gasket and flare with the down pointing studs

I had to cut the webbing bar to spread the 2 pipes apart

A floor jack from the bottom can only ring the pipes up so fart

I used a L channel 3 foot bar to leverage the pipes up to the final position with the exhaust casting cover bolt hole as the pivot point




Put a rolled up rag tie wrapped to the end of the bar to prevent windshield damage

The donut gasket studs / nuts are X size I got from Welsh out of Ohio , quick normal delivery

The short reach course threads go into the exhaust castings , The longer medium treads ( 1.25 x 13 hex ? ) are for the nuts

The hardware stores have 20 different sizes of exhaust studs except for the size you need

EAC3823

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Genuine Exhaust Manifold-3.2/4.0 Litre (less 6.0 Litre) For Jaguar Xj 1995 - 1997 (from 720125 To 812255) (x300) Classic | Jaguar Land Rover Classic Parts

 

Exhaust Manifold To Pipe Flange Seal ( donut ) , Pipe OD is 60 mm

EBC9388A

Vee had a generic # he gave me and what fitted and somewhere in my pile of papers in the garage

Genuine Exhaust Pipe-front-3.2/4.0 Litre-non Catalyst (less 6.0 Litre,less Catalyst) For Jaguar Xj 1995 - 1997 (from 720125 To 812255) (x300) Classic | Jaguar Land Rover Classic Parts

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