[dom14]

Hey guys,

My RB30 has been giving me trouble again. Started cutting off while driving.
Now it can't be started at all.
I had a look and pretty much immediately realized it's an electrical issue.
It's dual fuel. The problem happens with both LPG and petrol.
Basically, electricity isn't getting into the fuel system solenoids.
If I give a direct connection to petrol solenoid it fills up the carby and starts without issues.
I'm pretty sure it's the same with the LPG, even though I didn't do it.
I had close look all this late arvo, but couldn't find any broken wires or weak earth points.
Checked all the fuses. They are fine.
So, I reckon it's either an earth issue or major wire is broken or corroded somewhere in the fuel system.
It has an immobilizer, which is working ok. Not sure if it has anything to do with this.
Basically, no problem with engine cranking and other electrics like lights, etc.

What is the best way to find the culprit?
Any tips, leads, advice will be gratefully appreciated.

Thanks guys.

 

[dom14]

I found the middle wire of the selector switch is hanging with the connector end not connected to any wire.

There's no doubt that's a problem.

The LPG dashboard gauge has three male sockets(pins). But, only two of them are connected. So, I thought the middle wire of the
selector switch came out of it. So, I connected it, but still no change.

I gave some 12V to that middle pin/wire of the selector switch via the fusebox.

The LPG solenoid clicked, which is a good sign.

Still no idea where the electrical disconnection or the earth problem is.

I'll post some picture of the gauge and selector tomorrow.

In the meantime, I'm wondering whether the middle wire of the selector suppose to connect to the one of the pins on the gauge!!!

I couldn't find any other wire or connector hiding under the dashboard for the middle wire of the LPG selector to connect to.

I have no doubts it's obviously disconnected, it's that I'm not sure it's the only problem.

 

[bigcol]

well now, many years ago, I had a 4.2 petrol/gas
and I was having problems with it

sometimes it would start & run ok in petrol - but not gas
sometimes it would be running in petrol no problem, then Bam cut out and not re-start

sometimes it would start and run on Gas - but not petrol
sometimes it would be running in gas no problem, then - Bam cut out and not re-start

replaced EVERY sodding relay

when I asked a fine Gentleman in the Western Patrol Club on a drive one day, ET to be precise
he suggested......... (no, not get stuffed)

the Tacometric Relay - which switches power to and from the fuel / gas solenoids..............

replaced that........

but at the same time, my mate and I found another problem

the Earth for the Electronic Ignition was almost completely stuffed
so at the same time, I went and replaced ALL connections for the Gas / Petrol system


and never had a problem again

I also had -
2 earth straps off the main battery
2 earth straps off the 2nd battery
1 earth strap from the Gearbox to the Chassis
and 1 earth strap from the Motor to the Chassis

 

[dom14]

well now, many years ago, I had a 4.2 petrol/gas
and I was having problems with it

sometimes it would start & run ok in petrol - but not gas
sometimes it would be running in petrol no problem, then Bam cut out and not re-start

sometimes it would start and run on Gas - but not petrol
sometimes it would be running in gas no problem, then - Bam cut out and not re-start

replaced EVERY sodding relay

when I asked a fine Gentleman in the Western Patrol Club on a drive one day, ET to be precise
he suggested......... (no, not get stuffed)

the Tacometric Relay - which switches power to and from the fuel / gas solenoids..............

replaced that........

but at the same time, my mate and I found another problem

the Earth for the Electronic Ignition was almost completely stuffed
so at the same time, I went and replaced ALL connections for the Gas / Petrol system


and never had a problem again

I also had -
2 earth straps off the main battery
2 earth straps off the 2nd battery
1 earth strap from the Gearbox to the Chassis
and 1 earth strap from the Motor to the Chassis

Thanx Bigcol. That was very helpful indeed. I'm onto the business of replacing+cleaning all the earth wires(I have been onto it for a while, then got slack when the fourby started going good). It looks like I have a major electrical inspection job for fourby. I won't be taking it on any trips until that's done.

 

[dom14]

When I gave the direct +12V from battery to the fuel selector switch's middle pin, all goes fine.

My logic says that this is kinda confirmation that this issue isn't caused by weak or broken earth connection. But, that's my logic and it can be flawed.

Assuming it is +12V supply connection breakage to the fuel selection switch, I need to find where the breakage is. Under the dashboard is quite a mess. I'm still trying to get the part of the dashboard, where the stereo system, LPG switch & few other switches fit on to. It's stubborn and won't come out. I can't see any screws holding it. But, I can see the need of pulling it out to have a **** look inside to see if there's any wire breakage or corrosion.

Another thing I've been wondering is whether this has anything to do with the faulty key barrel electrical contacts. But, then again, other electrics, accessories, etc etc are working fine, as far as I can see. I'm hoping the actual wire breakage/corrosion is inside the engine bay wire harnesses, rather than inside the dashboard. Inside dashboard jobs are PITA.

 

[dom14]

http://www.apexus.com.au/document/gauges/ga100.pdf

Following the above diagram of a standard LPG gauge(like the one I have on my RB30 Patrol), I'm now fairly certain the LPG/Petrol selector switch +12V comes from the LPG gauge. So the blue wire is +12V connection. Now, assuming this is the way my LPG system is wired, it's kinda certain sender unit on the LPG tank has corroded connection or the +12V connection to the sender unit is broken/corroded somewhere between the battery and the LPG sender unit. That's a whole lot of wire length to check. So, I reckon I'll back track from the LPG gauge and see where the connections go and look out for breakages/corrosion, etc.

 

[dom14]

Eureka! I found it!!!: :iconbana:

All the problems(well....not all of them) were caused by a hidden fuse. Contrary to what I believed from what I saw, there was so much hidden under a thick layer
of insulation tape. Not one, I found two hidden fuses. Second one is a redundant one, completely hidden under sticky tape.
I'll post the pictures soon.
Contrary to what I saw in the outside LPG wiring(which was pretty bad), the fuses were wired properly(but hidden) with fuse holders.
Contrary to what I posted above about the LPG gauge getting powered first and then passing the +12V to the fuel selector switch.
It's the other way around.

Above diagram of the LPG gauge indicated it correctly, I simply read it wrong.

The reason I misjudged it(where the +12V power get to the LPG gauge & Fuel selector switch) because that quite a few of wire connections were hidden under a thick layer of insulation tape behind the Fuel selector switch.
The power(+12V) to the fuel selector switch was wired directly from the accessory line of the key barrel.
Then a 10A fuse is wired to it(hidden under the dashboard, but not covered with insulation tape), then another 10A fuse just behind the Fuel selector switch.
No idea about the reason for adding a redundant fuse and then completely hiding it with a thick layer of insulation tape.
I'll post the pictures shortly.
Now, I need to find out the reason for the fuse to blow up.
There's a very good reason for that.
I'm still going ahead with replacing all the wires and connectors of the outside LPG wiring.
It's shockingly cheap and sloppy work. Some wires were simply joined and sticky taped.
I'll post the pictures shortly.

The +12V connection(The blue wire in the above pictures) was disconnected from some previous fiddling I was doing.
I think that caused me to misunderstand the whole thing, 'cos the blue wire's(+12V) disconnection from the Fuel gauge has nothing to do
with the LPG selector not getting +12V. Totally separate issues.

 

[dom14]

Now, it would be great to see some fella posting something on this thread. So far, other than BigCol, it's been me, myself and I. I feel like I've been talking to myself bit too much and wondering whether I need to see a shrink. :skull:

 

[Grafe]

You have done well!

There should be a law against the practices of electrickery that results in the perpetrators being placed on bull ant's nests and covered in honey after being beaten severely.

 

[dom14]

You have done well!

There should be a law against the practices of electrickery that results in the perpetrators being placed on bull ant's nests and covered in honey after being beaten severely.

I would kill to see a bull ant's nest, even if it costs me my own butt(to be violated by bull ant bites)