l322 4,4 v8

[brutusmotorsport]

Hi, im Adam.
need little help with Range Rover. its not jag engine, i have prins system fitted, now the lpg will cut in usually about half mile down the road. i have actually done 20 mile journey each way to work and back with no issues.
but sometimes running on lpg it has happended few times now sometimes at 30 miles , 40 miles or even 65 miles. for some unknown reason the lpg will just switch off, it wont manually switch back, sometimes for a few hours.
im a capable mecanhic, but lpg is new system to me. im assuming that there is a valve that must be shutting off somewhere which turns off the lpg.
Does anyone have any ideas why what i could check please. The range rover came fitted with prins when i bought it, its actually certified and ulez exempt. {but i live in lincolnshire anyway}
regards Adam

[Gilbertd]

When it shuts off, does it do the same as it will when it runs out of gas? On a Prins, that will be a single beep from the switch and the LED will change to show running on petrol. There will be two, or possibly 3, solenoid valves in the system and if any of them are intermittent, the pressure will drop and the system will detect that as running out and switch back. There will be one solenoid at the tank valve and the other(s) under the bonnet. If there is a dirty electrical connection on any of those, it will heat up, the resistance will rise and it could drop out. Start with the one at the tank (presumably in the spare wheel well?) and work your way forward from there.

[brutusmotorsport]

what you are saying sounds correct. yes it does beep then change over to petrol. its never ran out as ive only filled it up once and only done about 150 miles on lpg.
due to me sillyness, but what does the solenoid look like? if i knew i would be able to narrow it down if i found it faulty. its all a learning curve for me.

[Gilbertd]

Solenoid coil looks like these here https://lpgautosupplies.co.uk/product-c ... lectrical/, the one on the tank will be attached to something looking like this https://lpgautosupplies.co.uk/shop/lpg- ... l-tank-30/ and you'll have one under the bonnet looking like one of these https://lpgautosupplies.co.uk/product-c ... off-valve/

[brutusmotorsport]

cheers dude, i have a look at the weekend.

[Gilbertd]

You can check the solenoid coils easily enough with a multimeter, you'll be looking at a reading of around 13 Ohms on each one. Another simple check you can do is the coolant level. There's a temperature sensor on the reducer (a thing looking like this https://lpgautosupplies.co.uk/shop/lpg- ... -solenoid/ that will be lurking under the bonnet somewhere) which is what causes it to switch over in the first place. If the coolant level is it can cool down once it is being used and the temperature drops down below the switching threshold so it will change back.

[brutusmotorsport]

update. had a look at weekend. Couldnt find any faults with solenoids they all checked out working. At a last rersort i removed the spare wheel cover and the lpg tank was saying empty when gauage at front was saying full, {weird}, So of we went to top up lpg which at 79p ltr it topped out at £62 so im assumimg its 80 ltr tank. Then lpg worked again, how long for i dont know yet as the Range Rover only goes out on a weekend or if friends over. Not sure how many miles im expecting to get but if i got 200 that would be fab.
Lets wait and see.

[Gilbertd]

As your £62 at 79ppl works out at 79 litres, it's more likely a 100 litre tank as they should only ever fill to 80% full. Gauges are never that accurate at the best of times but it sounds like you've got a different gauge sender fitted to what the software has been told you've got fitted. There's different senders and the software has an option where you tell it what you have but if that is incorrect, there's no telling what it will read. I run a 4.0 litre P38 Range Rover (previous model to yours) and that takes 67 litres to fill to the max which gives me a range of between 200 miles of general running around and up to 230 miles on a long run, so you should get 200 at least, maybe more depending on how you drive it and whether you spend all your time stuck in traffic or not.

[brutusmotorsport]

ive actually got the correct gauge fitted, it did work previously as it was completely empty the first time i filled it up according to the gauge. but your are correct otherwise. ive worked it out at the last full tank i managed 230 miles before realising it had actually run out. so im going to see how i get on this time. thank you for your kind response.

[LPGC]

If you have the correct level sender fitted, which seems to work correctly most of the time but shows full when it's actually empty, then chances are that the sender is faulty. A correct spec sender could be of various makes/designs. Some designs use a resistive strip (like a potentiometer), other designs use an array of resistors or semiconductors.... All level senders can fail in a way in which the sweeping arm doesn't make contact with the resistive strip or array at some point(s) around it's range of travel, in addition the array type can have failed resistor(s)/semiconductor(s).

One way in which (especially) the array type can be damaged is if the sender earth is connected to the tank solenoid earth. Then, if that earth goes bad, if the solenoid coil goes bad (short-circuit so drawing too much current) or especially if both (earth and solenoid) are bad the 'earth' voltage at the sender can be 'pulled up' to a few Volts or you can have a situation where the tank solenoid coil tries to earth via the sender unit... while some of the sender units are polarised and can be damaged by that few volts of reverse voltage to the earth connection or over voltage.

[brutusmotorsport]

the sender on the tank was reading empty, the prinns gauge on the dash was reading full. your are correct in a way, im still yet to drive it too see how it goes. as its only weekend car, im waiting until i actually get the chance to use it. ill certainly report back when im able to drive it and see how the lpg performs.
thankyou for your help.