small backfire now won't fill?

[DavidL]

Seems odd things to be related?
I've never had an issues filling the tank, slow when its very cold.
I gave it some beans going up hill through some running water and there was enough of a pop to make me jump but the car ran well enough on the way home. Next journey telltale signs that the tank was empty. Car runs fine on petrol.
So I assume it ran a bit lean on WOT and an empty tank. Its an old single point system on a 4.2 v8 range rover so I assume it has no blow back control - can you fit one?
So I trundled up to fill and it just wouldn't. I might get a few pence in and then nothing or just nothing. The pump clearly works as it had a previous dispense on it.
I spoke to a local lpg place who felt I just needed to keep the trigger pulled for longer which I will try but I was a bit concerned about doing damage somehow but apparently that's unlikely.
So any thoughts - are these 2 things linked?
Thanks

[kbs]

Some pumps are fussier than others.
Some pump a small amount of gas then check for the presence of pressure to ensure the tank it is filling is not holed.
So if your tank is truly empty, some pumps take a bit of faffing before they will fill.

One of the brains on here (Gilbert - I think, sorry if thats wrong) suggested making a hole in the air box (between filter and engine) then taping over with duct tape. In the event of blow back - the tape blows off. If you want something tidier, there is a big range of 'cat flap' devices available.

[Gilbertd]

Sounds like your diagnosis is spot on and that it was very low on gas so giving it welly meant it ran lean causing the backfire. However, I very much doubt that has anything to do with being unable to fill it. There is a spring loaded non-return valve in the filler and it isn't unknown for them to stick, especially if there is no dust cover over the filler and it gets a regular dosing of general road muck. Simple cure is to poke a long, thing screwdriver into the filler and, while wearing some nice thick gloves, give the non-return valve a poke. Depending on how well it is stuck, you may need to give it a good poke or even whack it with something. The pipe between the filler and the tank will be full of gas (unless you have run it completely dry and used that up too) which will spray out, hence the gloves. If you want to hold the valve open and give it a squirt of WD40, it won't do any harm and may stop it sticking again in the future.

My Classic LSE had the filler on the side of the towbar bracket with no cap and used to do the same once or twice a year. A long screwdriver and a whack with a pair of pliers would sort it out every time. The cheap blow back protection should be between the throttle body and the MAF sensor (I assume on a 4.2 you have a hot wire 14CUX system and not the earlier flapper type) so it will prevent damage to the MAF. Using duct tape has the added advantage that you have the sticky side on the inside in the airflow so it acts as an additional air filter.

[DavidL]

Thanks. Yes its a 94 LSE softdash and I've just spent a fortune having the bodywork tinworm eradicated (its got a bulkhead now!) so I don't need to be running it on expensive petrol.
The filler is on the towbar but it does have a cover and looks clean enough. I'll give it a poke as you suggest.
It has a K+N filter on it and the under bonnet insulation looks like its have a good blow back in the past - possibly the point the air box disintegrated and the K+N went on maybe. Before my time though.
Just confirm to me that I can't do any damage if there is a blockage and I've got the filler attached and trying to fill.
My feeling is that there was more excess gas on removal of the pump than there usually is post a normal fill but I could be wrong.

[Gilbertd]

You won't do any damage as the pump will not pump above a certain pressure. There is the non-return valve in the filler and another at the inlet on the tank so the pipe between the two will be full of liquid gas. When you fill there is also liquid gas in the filler nozzle between the valve in that and the non-return valve which is the gas that escapes when you remove the filler gun. It may be that it is the valve at the tank that has stuck, unlikely but always possible I suppose, so when you remove the gun you are letting some of the gas out from the pipe from the filler. As said, try giving it a poke to unstick it and if that is free, then just stand there like an idiot for longer with your finger on the button, if it is the tank valve it will lift off it's seat sooner or later under the pressure from the pump.

Mine was a '93 hard dash LSE, the last of the hard dash versions, in metallic green with the very dark brown, almost black, leather interior. It had 185,000 miles on it when I sold it and the guy that bought it was pleasantly surprised at how good it was. It pulled like a train and would cruise at 80 mph with a loaded car transporter trailer on the back on the French Autoroutes. I used to get around 200 miles from a 60 litre fill of LPG as it had a vertical toroidal tank fitted in the back where the spare would normally stand. The spare then stood on the opposite side and when both had the carpet covers on them it just looked like I was carrying two spares. It had the odd battle scar on the outer bodywork from where the previous owner had done a bit of green laning and I'd had the rear crossmember, sills and boot floor crumbly stuff replaced with actual steel so I know what you've been through. A friend has recently bought what on the outside appears to be an immaculate '94 LSE but it has been standing for 8 years. The water has got to the top of the bulkhead, rubbish has clogged the drains at each end and the entire bulkhead is in two pieces. One bit attached to the bottom of the windscreen and the other bit attached to the top of the firewall and nothing joining the two together. I'm going over to Holland in January and collecting a complete rust free bulkhead that he has found and then the welding will start in earnest!

[DavidL]

Did you post on rangerovers.net about the bulkhead? I seem to remember it.
I worry when I see cars up for good money but with no evidence of bodywork.
I don't care how shiny it is if it hasn't been apart it will be rusty and not worth the money. I 've got lots of photos!
Still needs the cosmetics done and probably a new cam and followers but hey its only money!
I'll let you know how I get on
Thanks

[Gilbertd]

I didn't but he did when we first started pulling it apart and found out the state of it. It's a really nice car with only 2 previous owners and both of them celebrities so it has history too. Weird part about it is all the usual places they go (rear crossmember, sills, inner wings, boot floor, etc) are fine, it's only the bulkhead.

[DavidL]

I had a quick look and a poke today. Nothing obvious moved.
It looks very clean but does it look as it should?
There is that odd bar at a funny angle.

[Gilbertd]

That's how it should look. The bit that needs a poke is the inner circular part behind the bar.

[DavidL]

The black bit or the inner of the 2 brass rings?

ETA Sorted thanks. No problems there.
I'll just have to leave the pump connected longer and hope that's ok.
Thanks again

[Gilbertd]

The inner of the two brass rings.

[DavidL]

Well I had another go today and it filled fine. I didn't feel I encountered any resistance yesterday when I check the valve but maybe it was enough to cause problems.
Only slightly confusing thing was that I could only get 50 litres in when if it was properly empty it would be 60l for the 80l tank.
Ah well I'll run this through and see how it goes next time. Car runs fine on both.
Thanks for all your help.