New RRC classic project, it backfired when starting on LPG and now wont start...

[rpo83]

Hi Brains trust, i have just bought a 1988 RRC project(unreg), i towed it home on Saturday.

The owner told me it starts on petrol then automatically switches to LPG, the install was done by LPG1 in Lilydale in 2007. I have been working on it over the past 2 days, fixing little stuff and generally having a good look at what i got for my money. It all looks good, the fuel gauge was reading empty, so i thought i'd play it safe and throw 10 litres of 98 in the tank to make sure it starts so i can move it around my yard, when i opened the petrol cap, i was shocked at all the rust and scale in the filler neck. I put the fuel in and noticed the gauge didn't move... This was yesterday, today the gauge reads 3/4 full, so there must be a ton of crud in the tank and filter and pump.

It doesn't start on petrol, after about 10 seconds of cranking it will start to splutter into life, then clear and run beautifully. Today when starting it, it backfired and hasn't sounded like it is trying to start since, it just turns over like there is either no spark or fuel. I looked over everything and couldn't see any thing obvious, but i did notice the manual primer is locked solid, feels like it is under big pressure..

Here is a pic of the Rangie being towed home and the engine bay. Any ideas would be greatly appreciated

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[bee utey]

1. The fuel pump in the tank is probably seized with rust, a common problem with neglect and age. A universal or VN Commodore pump replacement kit will do the job just fine.

2. There doesn't seem to be any backfire protection between the engine and the mass air flow meter, and that has probably been damaged beyond repair. Take off the hose between the air cleaner and the MAF and see if the internal flap still moves.

3. The LPG mixer has a cover held on with 5 screws, take that off and look for damage to the diaphragm and its cast supports. The diaphragm is lifted by downstream vacuum same as with a SU or Stromberg side draft carby.

4. Once you have the petrol tank out, cleaned and the fuel pump replaced, make the decision as to what fuel you want to run on. If both, you'll need to fit an anti backfire flap downstream of the MAF or it will be damaged again. Otherwise pick one fuel and stay with that.

[rpo83]

Thanks bee utey,

I'll strip all the bits on Friday and have a look, what would you recommend for backfire protection?

On a separate note, i'm trying to find out if i need to get the lpg tanks retested before i present the car for a rwc test, the instal is just over 10 years old, from all the paperwork i have downloaded from vicroads, i have not found a conclusive answer, hope you can help, as i'd rather remove the tanks myself and get them tested before i present for a RWC..

[bee utey]

Good quality backfire protection devices are getting hard to find. The wholesaler/importer I used to buy them from is now gone. AMR Manufacturing in Melbourne used to do one with a plastic flap, they would break and dislodge after a few backfires. I would then make up a replacement flap out of 1.6mm galvanised steel sheet. They are very old technology and are generally fitted to stuff from the late 80's and early 90's only.

AMR Manufacturing - Back Fire Valves (https://amrgas.com/back-fire-valves)

LPG tanks should have a riveted tag inside the valves area, the one on the exhaust side should be visible. The last test date is in the form of MM/YY (e.g. 05/07) and of course should ideally be under 10 years ago.

[DoubleChevron]

that looks liek an air flow meter ... I bet it's been blown off the induction side. Cars usually will not run once that happens. Though if it starts easily, it will start and idle, but not run as soon as you open the throttle ( as the idle switch on the throttle spindle must take the AFM out of the run circuit).

check all the hoses and connections. My old Citroen usually blows the inlet off the turbo if it backfires through the induction (it does it about once every 5 years).

seeya,
Shane L.

[rpo83]

Thanks guys,

with xmas, i haven't had time to look at the rangie, but i have been thinking about what i want to do with it long term, so i'm throwing around ideas of fitting a diesel, removing the LPG or leaving it dual fuel...

I want to run 255/85R16's so it looks like an engineer is going to be required, hence the reasons for throwing around the idea of repowering...

[DoubleChevron]

diesel ... with LPG fumigation given its already fitted :D