LPG Playing up... by Zeb


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Zeb
They say bad luck comes in threes....This week, I discover a rear spring has broken....then I become semi-disabled with a trapped nerve, now, having been forced to collect son from a hockey tournament with said immobilised arm, the LPG (Liquified Petroleum Gas) is on the blink!

All seems well, it makes to switch over and then acts like it is running out of LPG (half a tank in it)...and starts to die then switches back to petrol and either bleeps furiously at me along with all the LEDs flashing or just bleeps slowly with no LED (Light Emitting Diode) flashing. Solenoid appears to be doing its job...any thoughts folks?

Posted 13 Jun 2012, 15:58 #1 


Mad-Monkey
When I had no lights my ECU (Engine Control Unit) on the LPG had fried (my fault), I know yours is intermittent with lights on or off but have you had any water round the ECU? Or jump started the car?

Posted 13 Jun 2012, 16:24 #2 

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Zeb
Nope, neither... the lights flashing are a warning...will try and find out what it all means....when they don't flash they do still work as they should..if you see what I mean..

Posted 13 Jun 2012, 17:21 #3 


Mad-Monkey
Ah gotcha! Not a clue then sorry!

Posted 13 Jun 2012, 17:24 #4 

User avatar
Bernard
Could be a number of things. The flashing etc. is an indication of a fault present. Unfortunately it isn't clever enough to display what it is.
You could hook up a PC to the data link of the LPG ECU to see what's going on or go through a couple of visual checks to see if you can spot something.

Can you hear both solenoids working when it tries to switch? The solenoid at the front may be difficult to hear as I seem to remember that it had to be mounted low at the front as the traction control system was in the way of where I would ideally have mounted it. You could test for low pressure gas at the small flexible pipe which connects from one injector block to the pressure sensor. Gas should be around 1.5 bar on the low pressure side.

Check that the flexible hoses are OK especially the two smaller diameter lines to the pressure sensor.

Check the wiring at the 2 thermal sensors have not cracked as they enter the sensor body. One on one of the injector blocks and the other mounted on the vaporiser.

That's about it of the common problems.
I don't like signatures, they take up too much screen space.

Posted 14 Jun 2012, 06:20 #5 

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Zeb
Thanks very much Bernard...plenty to go on there....I will do all the visual stuff but I have no leads / software to do an ECU check nor owt to check the gas pressure with...hope it is something visual!

Posted 14 Jun 2012, 06:30 #6 

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Bernard
You don't need a gauge to do a rough check on the pressure, it will either be there or not. Just undo the small flexible from the injector block and you should get an idea if there is gas there. Especially if you are still smoking your Rover owner's pipe. :shock:

So the procedure is to start the engine and switch to gas when ready. The flexible pipes should now be full with low pressure gas. Switch off ignition and loosen the pipe. There should be a relatively small quantity of vapourised LPG released as the pipes drain down. There is no liquid gas in the flexy pipes so no danger of freeze burns to the hands.

Let's see what happens before we start to delve deeper and get all technical.
I don't like signatures, they take up too much screen space.

Posted 14 Jun 2012, 09:16 #7 

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Zeb
I will go give this a go....

Posted 14 Jun 2012, 11:16 #8 

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Zeb
Strange but true....my shoulder injury has stopped me trying to fix this problem thus far....but today, I just idly switched on the LPG system to see if it had done the oft noted MGRover thing of curing itself......and it had! Switched over sweetly, ran beautifully and not a kangaroo leap in sight.... No idea what that was all about..!

Posted 20 Jun 2012, 16:23 #9 

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Bernard
It's because I had threatened it. A variation of what we used to call the 'engineer is present effect'.
I don't like signatures, they take up too much screen space.

Posted 20 Jun 2012, 21:23 #10 

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Duncan
I have often used the 'soldering iron is present' effect on a variety of electronics.

The other oft encountered problem is oxygen starvation. Simply remove the lid and it will work fine again for a while.

Sometimes the only answer to these kind of problems is to perform percussive maintenance.
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Posted 20 Jun 2012, 21:37 #11 

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SpongeBob
The reverse often happens to me. In an attempt to fix things I often end up making them worse than when I started.

The adage of "if ain't broke... it soon will be" was true yesterday when I tried to descale a coffee machine (at work). The machine sounded much quieter when I had finished. Shame no water came out... :( After a few hours of fiddling and trying to purge the machine and generally threaten it, all hope was abandoned. The tell-tale sign was the faint whiff of over-cooked electronics. Unfortunately devices never seem to recover once that odour is released.... :gmc:

Posted 22 Jun 2012, 21:00 #12 

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Wheelnut
Had the same problem on mine, it cut out and acted as if the tank was empty, run a diagnostic at my mechanics no faults shown, the only suggestion was a temporary stuck valve, works fine now no problems at all, just a thought?
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Posted 05 Sep 2012, 13:06 #13 

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Zeb
Well, Bernard worked his magic from a distance....she is now fully functioning again with a new tank solenoid...:D

Posted 05 Sep 2012, 14:13 #14 

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Bernard
I'm pleased that this is now resolved. :-D
I don't like signatures, they take up too much screen space.

Posted 05 Sep 2012, 16:30 #15 


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