removing lpg

Tue Mar 09, 2010 1:04 am

Is there a valve or cut off on the gas cylinder?

I need to take the lpg kit out and its bloody full.

Tue Mar 09, 2010 1:09 am

there should be a manual shutoff valve on the tank itself.

once it's screwed shut, start and then try to switch to LPG - just to be sure!

it'll de-pressurise the system too

Tue Mar 09, 2010 1:13 am

gareth wrote:there should be a manual shutoff valve on the tank itself.

once it's screwed shut, start and then try to switch to LPG - just to be sure! it'll de-pressurise the system too

Can't try that as the radiator hose has popped, so no heat to the vapouriser.

Tue Mar 09, 2010 6:00 pm

it'll still run of LPG if there's any still flowing. if it's cut off, the engine will stop. just don't run it for ages

Tue Mar 09, 2010 7:54 pm

There will be a manual valve on the inlet to the tank, but there's a non return valve on that anyway.
The outlet may or may not have a manual valve as well as the electric valve, and if it has one, it may not be obvious. (the one on my E34 is a screw inside the stem of the solenoid).
Either way, if no power is applied to the solenoid, no gas will escape from the tank when you disconnect the lines, providing everything is in working order.
Note that I said "no gas will escape from the tank"! Plenty will escape from the pipe to the front of the car when you crack it off - so much that you will be convinced that it's coming from the tank.
To reduce this a bit, run the car on gas with the wires pulled off of the tank solenoid. This should use up most of the liquid and just leave mainly compressed gas.
Remember that LPG is heavier than air, and can pool in hollows in the ground, or can enter drains. It's an order of magnitude safer than petrol, but petrol does have the advantage that you can see the stuff!

Wed Mar 10, 2010 1:35 am

I couldn't seem to find any cut off, so i just started by undoing the inlet connection, just a bit of gas released. Doing the rest tomorrow

Wed Mar 10, 2010 1:36 am

Oh, forgot to mention, there are 2 red wires coming from a relay, which are connected to a plug below the inlet manifold area (passenger side)

What are these for?

Mon Mar 15, 2010 4:24 pm

injector disable, joined by your LPG ECU until you switchover to LPG, when it will disconnect (unjoin them) to disable your injectors. If you are removing the complete LPG install (why?) then you will need to join these together.

Tue Mar 16, 2010 1:00 am

johnlouis wrote:injector disable, joined by your LPG ECU until you switchover to LPG, when it will disconnect (unjoin them) to disable your injectors. If you are removing the complete LPG install (why?) then you will need to join these together.

Removing from the donor car to fit to my cab. So where do i connect these red wires to?

Tue Mar 16, 2010 8:49 am

FMH wrote:Removing from the donor car to fit to my cab.

I see! Makes sense now.
Before we get any further into this, you need to give us some details of what you have - most importantly whether it's a first generation system(open loop; no control), second generation (lambda controlled closed loop) mixer system, or even a third generation (vapour injection) system.
Do you have a LPG ECU? Is there a lambda sensor fitted? What make is the vaporiser? What does the changeover switch look like, and does it have a maker's name on it?