How difficult is DIY installation?

[v8vroom]

As per the title,
I'd imagine the simple answer is "hard" for someone who has never done it before, and I suppose installation is more or less the same, but perhaps car specific.

My fantasy:
Remove the LPG kit from my current blue XJ8, and swap it into a black XJ8. (it's the cheapest option when compared to respraying my car)

1. Is there guidance online on how to fit the kit?
2. Should I really tackle something serious?

[Gilbertd]

If they are both the same engine then what you are looking at is a take it to bits and put it back together job, just taking both to bits and putting both back together but with some bits swapped. If I was going to do it, I'd swap the inlet manifolds with the injectors over from one to the other (rather than drilling and tapping one and having to plug the holes on the other). Wiring should be straightforward or you could even swap the engine bay wiring looms over complete with the LPG wiring.

I wouldn't call it hard at all but it just depends on how confident you are in taking things apart and being able to put them back together and them still working.

[Brian_H]

Couple of tips to consider

Run the tank to empty before you start doing it (they are heavy enough as they are without adding more weight to them!)
Consider new pipe to run under the car and clips to hold it - particually if its done in copper pipe at the minute

You may have a fuel return fitted - Some Jags need them, depends if its got a return on the petrol system from factory (Simon might advise on that?)

Where the filler is may be something you want to change.

You might want to consider running it past an installer afterwards to check you haven't done anything that might cause problems down the line, and check its getting hte best performance you can from it.

You may also want to consider an injector/vapouriser rebuild whilst the bits are out - depends how new the kit is, what kit it actually is, and how well its currently working though.

Also depends what your doing with the Blue XJ8 afterwards - if its being sold you obviously want to put it right, if there are other reasons your not doing so then it may be a bit easier.

Also consider if its the same engine on both - this isn't a show stopper, but may need the calibration checking over (that probabbly wouldn't be the worst idea in any case).

[LPGC]

Whether or not it needs a fuel return depends on the model year, if you can read petrol pressure in OBD live data it will need a fuel return. Later models need one early models don't, the cut off year will be early 2000's.

Depending on model year and what LPG ECU you fit it may or may not need 2 x AEB124's (or similar), more likely if fitting an older AEB based ECU such as an old AEB2568 Romano ECU. The AEB124's are effectively a block of resistors which pull down the electrical resistance the petrol ECU sees as injector load when running on LPG. If it needs AEB124's and you don't fit them you'll get 'injector open circuit' errors, not immediately but on the 2nd day you run on LPG. AEB124's or similar could be added to an existing install.

If it has an air suspension pump at the rear (more likely on a LWB model) it may need relocating during fitting a spare wheel tank, not too difficult.

The rear of the spare wheel well slopes upward toward the rear, can fit a bigger tank in XJ8's by 'massaging' the floor of the spare wheel well with a lump hammer! Come to think of it, you said on a different thread that your existing XJ8 tank doesn't take as much gas as you'd expect... If it has the valve at the front and the tank slopes up toward the rear it won't take as much gas as you'd think because the valve will be at the deepest end. Very likely you could fit a bigger tank than the one you have anyway.

Needs a lube system.

The water to reducer plumbing can be a pain on XJ8's (and other Jags) but is probably similar across most XJ8s so you can just copy that plumbing... But before copying first make sure the LPG system and heater work properly on the current XJ8 in all conditions including heater on/off.

[Pinger]

From an amateur's perspective - how disagreeable is the blue?
I've come come close to what you are proposing. What I've done is replace just about everything (except electrics) from the tank forwards on my truck. Different from what you propose as the vehicle was already LPG equipped, Similar as many components were different from what was there before and required new mountings and routing of pipework. It is a lot of work. The new pipe was awkward and that was on a truck where access is way better than it will be on your Jaguars.

I make two suggestion which are deviations from your proposal.
1). Keep what you have - unless you really really want black over blue.
2) Leave the blue one with it's LPG kit and buy new components for the black one. Crib the exact layout from the blue one and save yourself the grief of having to dismantle it. (Removing the old supply pipe was one of the most onerous tasks on mine. It shouldn't have been - but it was). When you are done you have two LPG converted Jaguars and the blue one will surely more easily find a buyer with petrol prices set to remain high for the foreseeable future.

[Brian_H]

If its a copper feed pipe, new its not brilliant to work with, after its been sat on the car for some time it seems to get worse.

You can use poly pipe as an alternative, which is a lot easier to work with particually if you haven't done this before and moreso if you are working on the ground under the car rather than having access to a lift.

[v8vroom]

Hi all,

After forgetting about this project, the thought popped up again as I'm eager to learn more to see if it's actually feasible. The plan is to understand absolutely everything, relay my understanding of the job, and if all is accepted by you experts, then I'll consider tackling the job.

Pinger is correct - I will not dismantle the current blue Jag, as it'll be a headache. So if I am to proceed, I'll purchase a DIY kit which brings me to the following question(s) (I have not done research yet so this is all assumptions)

1. Any recommendations for a supplier/brand?
2. What system is best for the car? Multipoint system with individual injectors or fully sequential multipoint (assuming they are suitable)
3. Is drilling an absolute necessity for the latest system(s)? If so, are there guides on how/where to drill
4. Does a guide already exist here? I'm only seeing this which is outdated by a decade, which might not be an issue if there haven't been any drastic changes to the installation methods) viewtopic.php?t=8148

[LPGC]

Don't follow Tooless' installation guide lol !

[v8vroom]

Don't follow Tooless' installation guide lol !

Of course not, I'm just surprised it's the only DIY guide I can find.

[Gilbertd]

1. Any recommendations for a supplier/brand?
2. What system is best for the car? Multipoint system with individual injectors or fully sequential multipoint (assuming they are suitable)
3. Is drilling an absolute necessity for the latest system(s)? If so, are there guides on how/where to drill
4. Does a guide already exist here? I'm only seeing this which is outdated by a decade, which might not be an issue if there haven't been any drastic changes to the installation methods) viewtopic.php?t=8148

1. Tinley Tech, now called LPG Auto Supplies (https://lpgautosupplies.co.uk/). Speak to Mick there and he will be able to advise you which will be your best option as far as brand is concerned. Personally I'd go for one of the Italian AEB based systems (AEB or Romano are the two Mick does).
2. Multipoint with individual injectors are fully sequential these days. There used to be some early multipoint systems that batch fired the injectors so on a V8 they would fire the injectors on each bank alternately but you won't be able to find any of them these days, they are all fully sequential (although some may have a setting in software to batch fire if being fitted on an older car (like the Range Rover Classic with 14CUX petrol system) that batch fired the petrol injectors.
3. Yes. Where you drill depends on the engine but you need to drill as close to the petrol injectors as possible so the fuel enters the manifold at the same place. You can buy spacers with nozzles that fit between the manifold and petrol injector but those that have tried them have found it raises the petrol injectors up so the fuel rail doesn't fit well and can introduce intake air leaks.
4. Not on here but https://drive.google.com/file/d/1QUYczd ... share_link is the installation guide for the OMVL (AEB based) system and this https://docs.google.com/document/d/0Bzx ... ue&sd=true is the code of practice for installations.