Thread: Problem after LPG installation.No start sometimes

Well, I'll take a stab in the dark, on this one .....

Basically your saying that
Prior to the install .... it ran like a dream
After the install .... it runs when it feels like it

With common diagnosis being a problem with a wire going to the ECU



When they hook up the wiring for the gas ... they would splice into the injector wiring loom to knock out the injectors (Stop them from working) when it's running on gas

If the gas installer just used a "Quick clip" to make this join instead of soldering it .... then you may have a dry joint ....so look to where the gas installer spliced into the loom and check his joining method



What I can't figure out tho is .... the ECU and it's plug / loom are easy to get to .... If the Sparky had it apart to test it, and declared the pin in the plug, "knackered",, Why didn't he just fix it straight up?? ... as it was right in front of him

Mike

Originally Posted by mike 90 RR

Well, I'll take a stab in the dark, on this one .....

Basically your saying that
Prior to the install .... it ran like a dream
After the install .... it runs when it feels like it

With common diagnosis being a problem with a wire going to the ECU



When they hook up the wiring for the gas ... they would splice into the injector wiring loom to knock out the injectors (Stop them from working) when it's running on gas

If the gas installer just used a "Quick clip" to make this join instead of soldering it .... then you may have a dry joint ....so look to where the gas installer spliced into the loom and check his joining method



What I can't figure out tho is .... the ECU and it's plug / loom are easy to get to .... If the Sparky had it apart to test it, and declared the pin in the plug, "knackered",, Why didn't he just fix it straight up?? ... as it was right in front of him

Mike

Those were my thoughts. A lot of people don't like working on Rovers , it's all too hard for them.
The LPG mob had the car for 4 hours but out of their kindness they only charged for 2hr They reckon they had to get a wiring diagram from Land rover.
Considering this mob has been installing LPG systems to land rovers here in Victoria for many years and are supposed to know there stuff I would think they would know Rover wiring back to front by now.
The install was pretty Sloppy to. They just have a bunch of relays dangling behind the drivers panel that accesses the wiring looms. The tanks in the boot were covered with a loose bit of chip board, second hand with a corner broken off.
This company also did mine many years ago and the wiring was neat, relays were screwed to a bracket and fastened.
With the Govt LPG conversion rebate the quality of workmanship has headed south, get them in and out as quick as and make the $$$$$$$ it appears.

Ok, I've had a look at the Disco and it appears that there may be an earthing problem from the Fuel pump Relay.
The Switching earth wire intermittantly works. The RACV ran another earth wire to the body and feed the other end into the relay earth, the car will start but runs fast.
at other times it will not work with this extra earth, and will start once it is removed. We loose all led indictor lights for the Petrol/LPG switch when this fault occurs.

Me thinks that 1 of these guys ..... LPG installer / auto electrician ..... is not doing their job

Mike

Ok, I've had a look at the Disco and it appears that there may be an earthing problem from the Fuel pump Relay. The BLUE thin Wire at right side
The Switching earth wire intermittently works. The RACV ran another earth wire to the body and feed the other end into the relay earth, the car will start only on lpg
at other times it will not work with this extra earth, and will start once it is removed. We loose all led indicator lights lpg fuel gauge on the Petrol/LPG switch when this fault occurs.

Since the LPG people are still on talking terms - get a wiring diagram of the LPG switch from them, and perhaps some notations as to how they spliced into the loom. Then you can start tracking down what does what ( and post pics for us in the brain trust.)

I just had a look at the wiring diagram for my 92 RRC which has a similar setup to your 14CUX.
Although the colours are different , the fuel relay both earths and is triggered through the ECU. This looks like the light blue and white green. Just have a look at the relay and it should have which pins are trigger and earth printed/stamped on it. But be careful as you do not want to damage the ECU

Are you aware that the fuel relay is turned off by the ECU after 3 seconds of cranking until the ECU detects engine revs? This may be why it shows intermittent.

Seeing it did not happen prior to the gas conversion my guess is it is something to do with the splicing in of a switching relay to stop the pump when the car is switched to LPG. maybe the pump should be left alone.
Regards Philip A

Thanks for all the replies guys.

I've solved the problem.

the relay displayed was not the problem. Even though all the experts had a go at it and hot wired it to get the disco to run, alas only on lpg

It was the next relay adjacent to it. I took a punt and replaced it and it solved all the problems.
I undid all the tape off the lpg installation and checked the solder joints on the injector wires.

A proper auto electrician should have diagnosed that with in 10 mins if they had the kick panel off and were checking the ecu. What ever that relay was it got the fuel pump working, as it would not run on petrol mode previously. I checked the fuel rail and there was no fuel pressure to speak off.
Now both Gas and petrol are working as they should
Any all is well now.