Bored? Please help me then!

[Marlowboy]

Hi all, hope everyone is keeping safe! Bit of help/ advice if you would be so kind, you have nothing else to do!
I was a Mechanic/ MOT Tester for many years but it was a while ago but still enjoy “tinkering” I have bought a BMW X5 LPG to......tinker with and boy, does it need some tinkering but I have plenty of time.
If a Petrol car will not start I know how to diagnose and get it running, the X5 runs on Petrol ok but I have a Vacuum leak that I’m working on, making a Smoke Machine at the moment, happy days. I’m sure it’s not switching over to gas. The “gauge” on the Dash shows no lights. I’ve found a loose Red wire off the Vapourizer next to the Tank but not sure I want to connect ot in case it’s been disconnected on purpose. The gauge on the Tank is showing 1/3 rd Full. Is there a procedure to follow to try and get to the problem. My local LPG Garage is closed but there is no hurry, just thought I’d “have a tinker” I hoped to be able to purchase a Haynes type book on LPG but there doesn’t seem to be one.
Any help, advice would be most welcome. Stay Safe!

[Brian_H]

The vapourizer wouldn't normally be next to the tank? Theres very little freely available info on lpg, but if you can identify the ecu being used in your system (hopefully on a sticker on the ecu itself) then it might be possible to find a wiring diagram to work out what it is. Alternatively take a photo of what you've found and upload it here, that might give a clue on the problem.

The vapouriser typically has 2 electrical connections, though either of them could be remote to the unit itself, you have the water temp sensor, and the shutoff solenoid. Sometimes mounted directely onto the vapouriser, sometimes they will be either on the coolant pipework nearby, or on the gas feed from the tank to the front (theres another on the tank itself).

Tank would usually be in the rear of the vehicle (due to that being where the space generally is for it) and the vapouriser up the front where the engine is.

[Marlowboy]

Hi Brian, thanks for reply. I’ve probably named the Part wrongly! The “ thing” I’ve called the Vaporiser is attached to the Tank which is indeed fitted in the rear wheel space. A Fuel feed goes into it from the Filler and then back out towards the engine. I’ve tried to upload a wonderful Photo but I’m having a problem, it’s saying HTTP Error and I haven't a clue what I’m doing wrong, where is my Daughter when I need her. I did Post a Photo in a previous Post titled Tank Removal on the 28th March, not the best Photo but it might help?
Thanks again, Martin

[Brian_H]

You might find the photo is too big for the forum. I think its limited to a couple of mb size.

[Marlowboy]

Brian, could it be a “reducer” that I’m talking about?

[Brian_H]

I've look at the post - the red one is the positive feed from the tank valve. That should be connected to one of the wires that run under the car to the front end, depending on your ecu it may be shared with the front solenoid feed, or may have a dedicated feed for it. If you've got a multimeter, then with it disconnected check the resistance across the two wires running from that coil on the tank, should see around 16-18 ohms. I'd suspect nothing wrong with it at this point, but it might have been disconnected to stop it switching over due to another issue. Only way you will find out really is to try it and see what happens.

Wouldn't be a bad idea at this point to do a fault code scan of the car itself if you can, and fix your vacuum leak before you start trying to fix the gas problem. Also worth you knowing that there will be a vacuum line running to the vapouriser (unit down the front in the engine bay, will be connected to the coolant system by pipes and the gas injectors by a hose). I'd suggest checking that the feed to the vapouriser isn't the cause of your vacuum leak (additional pipework rubbing against stuff worn a hole it it over time is possible). Should be able to prove that by removing the pipe from the manifold and plugging the resulting end as its not doing anything as it stands.

No its not a reducer your photo shows. What you can see is the inside of a tank valve box - like this i'd guess (2nd pic) https://tinleytech.co.uk/shop/lpg-tanks ... and-box-2/
These are reducers or vapourisers/Regulators (same thing but different names) https://tinleytech.co.uk/product-catego ... injection/

[Marlowboy]

Thanks again, I’ll have a look, love tinkering! I’m converting the Air Suspension to Coil Springs tomorrow so may be later in the week, no rush as I can’t go anywhere!