https://www.jaguarforums.com/forum/ 1986 - 1994 en Fri, 22 May 2026 21:30:05 GMT vBulletin 60 https://www.jaguarforums.com/forum/images/kirsch/misc/rss.jpg https://www.jaguarforums.com/forum/ https://www.jaguarforums.com/forum/xj40-xj81-25/matching-cylinderhead-296324/ Thu, 07 May 2026 17:41:20 GMT I am a rookie with this forum, so thanks for answering!! As a proud owner of a 1989 xj40 3,6 Sovereign with a damaged cylinder head gasket, I am actually overhauling an other Engine with the aim... I am a rookie with this forum, so thanks for answering!!

As a proud owner of a 1989 xj40 3,6 Sovereign with a damaged cylinder head gasket, I am actually overhauling an other Engine with the aim of exchanging the two.

So, I have a 9DPAMA Block (early 3,6 ??) fitted with an eac7077 cylinder head (late 4,0 ??), furthermore I have got an eac4002 cylinderhead, which I have already restored a few years ago.

My question is whether I can fit the eac4002 head in the 9DPAMA Block without getting an trouble, maybe you guys have more insights.

Greetings, Boris from Bavaria ]]> XJ40 ( XJ81 ) bfa1 https://www.jaguarforums.com/forum/xj40-xj81-25/matching-cylinderhead-296324/ https://www.jaguarforums.com/forum/xj40-xj81-25/6-0-litre-various-issues-296147/ Mon, 27 Apr 2026 23:33:34 GMT Hi together, in addition to my transmission my engine is now starting to tackle me. 1. Issue: the left hand catalytic converter is melted inside 2. Issue: the ignition coil of the left hand... Hi together,

in addition to my transmission my engine is now starting to tackle me.

1. Issue: the left hand catalytic converter is melted inside
2. Issue: the ignition coil of the left hand bank is slightly burned (probably caused by someone not putting on the ignition wire properly:icon_fryingpan:) -> this could possibly explain #1
3. Issue: on the right hand bank 4 out of six spark plugs are almost white, which would indicate they are running too lean
4. Issue: the oil consumption has increased over the past year, it is at about 1 litre per 1000km

Regarding issue #1 I have been looking for a replacement, but there are only cheap aftermarktet parts available which are said to be made of poor quality, can anyone tell me a source for a good replacement?

Issue #2 should be fixed by a new coil and cable, luckily.

Regarding issue #3 I have tested 2+2 injectors (2 from cylinders with good spark and 2 from cylinders with bad spark) and they tested almost equally (amountwise). So the injectors are probably not the issue. So do I also have an ignition issue on the other bank?

For issue #4 I made a compression test and found that the rear cylinders of each bank are slightly below the factory value (between 12,5 bar and 13,2 whereas the target value is between 13,6 and 16,3 bar). So I guess the cylinder head gaskets are about to give up. Or has anyone a better explanation?

Doing the head gaskets is quite a job according to what I have read so far, but paying someone for doing this is not an option. Looking at my faulty transmission I am not sure if am willing to take the task, knowing that even when it's done I am still in trouble on the other side of the crank. If I knew the transmission was fixed it would increase my motivation to do the engine as well, but if it turns out that is more serious that just the head gaskets, I might have fixed the transmission for nothing.

Any thought appreciated.
Oliver
]]> XJ40 ( XJ81 ) V12Lover https://www.jaguarforums.com/forum/xj40-xj81-25/6-0-litre-various-issues-296147/ https://www.jaguarforums.com/forum/xj40-xj81-25/93-model-cranking-but-not-firing-fuel-related-296144/ Mon, 27 Apr 2026 22:55:23 GMT Hi I have a problem with the car turning over but not firing. It started with loss of power with engine quitting, then OK for a couple of weeks then happened twice in my last trip, managed to get... Hi

I have a problem with the car turning over but not firing. It started with loss of power with engine quitting, then OK for a couple of weeks then happened twice in my last trip, managed to get home, from then on won't start.

First thing i checked fuel pump relay (good), then bridged the relay socket pins 30 & 87 nothing from the fuel pump (in tank model) no purge noise but reading 12 volts, also checked socket at top of the tank 12v supply good (wiring to tank OK) so assumed fuel pump failiure, replaced with a new one yesterday. Once all put back first turn of the key up it fired and idles nicely, job done. However today won't start same issues as before, checked electrics again 12v to tank as before. but pump still silent.

I also tested the old pump and works ok. I presume there is some sort of float switch inside the pump as it works on its side but not upright.

Any ideas

Regards
]]> XJ40 ( XJ81 ) XtremeTi https://www.jaguarforums.com/forum/xj40-xj81-25/93-model-cranking-but-not-firing-fuel-related-296144/ https://www.jaguarforums.com/forum/xj40-xj81-25/my94-xj12-wont-turn-over-but-battery-good-296061/ Thu, 23 Apr 2026 14:31:55 GMT My 1994 Xj12 is having issues with cranking over. I have checked the battery and it is good. I have cleaned the terminals on the battery and the inside of the terminals on the cables. I also... My 1994 Xj12 is having issues with cranking over. I have checked the battery and it is good.
I have cleaned the terminals on the battery and the inside of the terminals on the cables.
I also cleaned the end of the ground cable that hooks to the body sheet metal at the side of the battery.
It shows over 12 volts at the actual battery posts but when I turn the ignition key to the on position, the volt gauge on the dash shows WAY less volts.
When I try the key in the start position the stater does not engage.
I had to move the car yesterday after it had sat unused for a few days.
I hooked a large heavy duty battery charger up to the battery by clamping over the terminal connections on the cables and switched the charger to a start boost setting.
At first this did nothing but eventually after two or three minutes the reading on the dash mounted volt meter jumped up to show over 13 volts and the starter engaged to turn the engine over when the key was turned.

Anyone have any suggestions? Should I be jacking the car up to look at the ground strap on the engine (wherever that is located)? ]]> XJ40 ( XJ81 ) JensenHealey https://www.jaguarforums.com/forum/xj40-xj81-25/my94-xj12-wont-turn-over-but-battery-good-296061/