You say your going to remove it - if its still installed, is there a good reason why your not using up the lpg in the tank first? It would make it easier to deal with as it would reduce the weight of the tank. Or is it only partly installed now and not possible to do so?
I started doing work on the car a couple of months ago. I’ve replaced every single bush and ball joint on it, replaced both diffs, all 4 wheel bearings, etc.
Ever since I’ve had the car it’s had a bit of a misfire when cold for a few minutes until it had warmed up. Once it had warmed up it ran perfectly. After I’d done all the suspension work I had the car running on the ramp and the misfire started to really annoy me so I started checking thoroughly for vacuum leaks. I found one under the charge coolers so removed them. Whilst they were off I decided I’d replace the valve cover gaskets as they were weeping oil.
When the valve cover gaskets were stripped off I checked the valve clearances and found that on cylinder 1 (the one logging the misfires) there was zero valve clearance. In the end I removed the heads and you can actually see the way the valves have recessed into the heads despite it having flashlube installed.
It’s a common fault on these engines with LPG fitted. This one has done around 77k on LPG according to the service history.
I managed to get a brand new set of cylinder heads from eBay so I’m fitting these and am not refitting the LPG hence not being able to run the tank down before removing it. I could put 12v to the solenoid and use it for the BBQ though I guess. 🤔
1995 4.6 HSE - Biarritz Blue - Breaker
2002 4.6 Vogue SE - Alveston Red
2007 4.2 Supercharged - Java Black
2012 4.4 TDV8 Autobiography - Baltic Blue