There will likely be a feed from one of the O2 sensors to the LPG controller. It'll likely be a purple wire and be connected in the petrol ECU box. Disconnect it. The LPG system doesn't need it, it's there so you can monitor the lambda sensor output on the LPG software but it isn't unknown for a stray voltage from the LPG system to confuse the petrol ECU. Output signal from the RH bank sensor arrives at the petrol ECU on pin 16 of C0635 (24 pin black plug) on a blue wire so you will be looking for something tee'd into that.
Gilbertd wrote:
There will likely be a feed from one of the O2 sensors to the LPG controller. It'll likely be a purple wire and be connected in the petrol ECU box. Disconnect it. The LPG system doesn't need it, it's there so you can monitor the lambda sensor output on the LPG software but it isn't unknown for a stray voltage from the LPG system to confuse the petrol ECU. Output signal from the RH bank sensor arrives at the petrol ECU on pin 16 of C0635 (24 pin black plug) on a blue wire so you will be looking for something tee'd into that
hmm. the black box, with two lifty up tabs on top behind cruise control diaphragm? That's not coming out easy. It's well hemmed in by other gear. Lpg ecu is all installed around that. Can i unplug the lpg? Looks like there might be a direct feed to it from the battery with an inline 15a fuse? will pulling that fuse wield the same test????
It might but it depends on the exact LPG system you've got. Worth a try though.
This guy had exactly the same problem on a Thor fitted with a Prins LPG system https://rangerovers.pub/topic/354-02-sensor-voltage-fixed-low
tried it whilst waiting. No difference.
So is it the box behind the cruise diaphragm? Lift the 2 tabs and wiggle it out somehow?
Gilbertd wrote:
This guy had exactly the same problem on a Thor fitted with a Prins LPG system https://rangerovers.pub/topic/354-02-sensor-voltage-fixed-low
Interesting read. He had the idea of unplugging the lpg too. Except he says he removed both the positive and negative. I just removed the fuse at the battery end as i figured that would break the circuit. LPG wasn't lit up on dash so i assume it did??
I really need to be getting into this ecu box and poking about for that wire you're on about. Do the O2 sensors tell the LPG to turn on when it's up to temperture?
That's the one. You shouldn't need to wiggle it out if you are just looking for extra wires tapped into the ECU wiring. They should be fairly obvious as being extras.
Gilbertd wrote:
That's the one. You shouldn't need to wiggle it out if you are just looking for extra wires tapped into the ECU wiring. They should be fairly obvious as being extras.
Wires have a sort of corrugated plastic tube over them. Nothing obviously been tapped in. Does look nice and tidy under the bonnet so i think it was a really good install when done. Perhaps the wires are not obvious?
Do i just lift the two tabs and lift the black box out in one? upwards? sidewards?
If it's been done properly, the extra wiring should be made to look like it's part of the car. No idea how to get the ECU out on a Thor, I've got a GEMS and you don't need to lift it out, the connections are all on the top. But this is what RAVE says
blueplasticsoulman wrote:
Do the O2 sensors tell the LPG to turn on when it's up to temperture?
No, the LPG turns on when a temperature sensor on the reducer tells the controller it's up to temperature. The O2 sensors don't have anything to do with the LPG system, they are talking to the petrol system and the LPG system is slaved off that. Without a connection from at least one of the O2 sensors, when setting up the LPG system you need to be looking at a live code reader (to see what the O2 sensors are reporting) and the LPG software on a laptop. With the connection the LPG software will display the O2 sensor outputs so all the information is in one place. That's the only reason for the connection so disconnecting it won't affect how either system works (or shouldn't if they aren't arguing with each other).
Great stuff. Was looking for that in Rave. I'll get to it tomorrow when i get home. Since you don't have a thor, Do you wanna buy one? Full years test as of today. lol Nothing wrong with that one. Sweet as a nut on petrol and gas.
I know i seem to ask alot of questions but it does pay dividends. The 6 p'S. Prior Planning Prevents Piss Poor Performance
Thanks Mr G
Once cruise is removed it's the black box that has 2 lips on top, a bit like the under bonnet fusebox. Lift them and the black box folds open like the glovecompartment, the ecu is like a cassette inside.
Out of interest, whats in the box behind the battery? Thats got all sorts of wires coming out of it too.
and although it may be obvious, but i haven't done it, should i unplug the O2 and check there's 12v there?
On a Thor, nothing. That's where the ECU lives on a GEMS and for some unknown reason they left it in on the Thor. People often use it to keep jump leads, spare sandwiches or an LPG ECU. If there's wires coming out of it, I would suspect that's where the LPG ECU is living.
blueplasticsoulman wrote:
Out of interest, whats in the box behind the battery? Thats got all sorts of wires coming out of it too.
On a GEMS, the engine ECU. On a Thor it's just an empty box so, sandwiches, mini tool kit, or, more realistically it's where the LPG ECU is usually fitted
EDIT- beaten by Gilbertd, but we agree on sandwiches :)
Gilbertd wrote:
On a Thor, nothing. That's where the ECU lives on a GEMS and for some unknown reason they left it in on the Thor. People often use it to keep jump leads, spare sandwiches or an LPG ECU. If there's wires coming out of it, I would suspect that's where the LPG ECU is living.
Ok. Just looks factory. If it is LPG ECU, like i say it's be done rather nicely.
i'll post a picture of the lpg install on the other car tomorrow. Not quite as pro!
There's many bad installs of lpg, some of the conversions are more diy than professional install, instead of splitting and joining into the loom, they're plug and play, but it leaves a lot of excess wiring.
My system ( landi renzo) may not be the best around, but at least it was all soldered into the loom, so it's reasonably tidy..
Having that box behind the battery on the Thor is a god send, my LPG ecu is tucked away in there.
I keep a rag for checking my oil level and a couple of small hand tools in my box behind the battery.
right. Removed ecm.
Found blue wire that goes to pin 16. Followed it into the loom a bit and there's other stuff tacked onto it. Does this look standard???
https://ibb.co/kLRamQ (heat shrinked wires. are these an addition for the lpg??)
https://ibb.co/kUvqLk (blue wire for Bank 2, O2 Sensor with a red wire which ill assume is bank 1?)
https://ibb.co/f0NsY5 (heatshrink wires end up joining the blue and red wire. And theres a 3rd in there which im assuming is ground?)
now that i think about it and look at it. i'm thinking it is standard, and that the heatshrink is ground wires converging?
i've disconnected the lpg ecu. as a pre-emptive next move. The system is Tartarini Auto.