Switch over

[Hemi123]

Is it is normal for an lpg system to switch over to petrol under high revs when the lpg tank is not full (36 litres in tank, 102 litre tank, flashing reserve light)? Or does this mean that the system needs its pressure increased?

[Gilbertd]

If it does it under acceleration, it might just be caused by slosh in the tank uncovering the pickup pipe. Then you'll only get vapour rather than liquid so it will switch over due to a lack of gas pressure. If it does it simply at high revs, it may need the filters changing. It's not right though and increasing the pressure would, if anything, make it worse.

[Hemi123]

It does it under acceleration.

[andy evans autogas]

When you say it switches back to petrol does it bleep like its ran out of gas or does the switch light change from yellow to red ???

[Hemi123]

It beeps like it has run out of gas.

[andy evans autogas]

Is it a new thing that's just started or been doing it since the conversion???
If its been doing it since the conversion then it could be the placement of the multivalve / tank
If its recently started then check your filters or pipes under the car incase it's been jacked up and squashed a pipe.
Andy

[Hemi123]

It has been doing it since the conversion. Just after the conversion it used to do it all the time no matter how full the tank was and than the pressure was increased at the 1000 mile service and now it just does this when the tank is closer to empty than it is to full. The tank is a 4 hole toroidal and it is underneath the vehicle where the spare wheel used to be stowed.

[andy evans autogas]

Ok what car is it, what system is it, and where was it fitted.
Andy

[Hemi123]

It is a Jeep Commander 5.7 L HEMI. The LPG system is a BRC Plug & Drive with a Genius Max reducer and orange injectors. It was fitted at Birway Garage Ltd.

[Gilbertd]

The only thing that causes the pressure before the reducer to change is temperature so it will be the same with a full tank as an almost empty one. I suspect the tank has been installed so that the pickup is uncovered under acceleration rather than braking (when it wouldn't have much, if any, affect). Easiest way to tell is if your level gauge goes up or down under acceleration. If it drops then it is most likely that it is slosh that is causing the problem.

[andy evans autogas]

It would seem that you have a flow problem if the install is still under warranty then take it back to the installer, From experience with the plug and drive systems they don't always do as they say on the tin (plug & drive).it would seem that the system isn't up for the job. I as an installer had a similar problem about 2yrs ago with a Cadillac escalade pushing out 410bhp but after a couple of adjustments to the KME system it went out perfect & is now in the south of France running perfectly.

[Hemi123]

The pickup in the tank is adjustable? It is a GZWM tank. The guage leds that indicate the tank level do not change under acceleration.

[rossko]

Not adjustable. Its a case of installing the tank in the best orientation to begin with, some ways are better than others, but all are somewhat imperfect.

[Hemi123]

As it is a toroidal tank underneath the vehicle it would have to lay flat like the spare wheel it replaced. The LPG fuel line runs out of the tank on the NSR of the vehicle.

I am unsure if this is a problem with the LPG system or a limitation?

[Hemi123]

Based on my experience I would not recommend having an LPG system installed by Birway Garage Ltd.

[classicswede]

For what reason is that eaxctly.Has then been fursther issues that just this?

Have you tried getting in touch with BRCGB?

[Hemi123]

I generally do not think that LPG is very good. When it was first installed it operated pretty badly, in terms of cutting out under acceleration. I never quite understood why they would complete the installation with bad settings and than change the settings after 1000 miles so that it does that only when there is less than 1/2 a tank of LPG. I also think that the savings of LPG are not all that great, as to use a tank of LPG requires the use of 1/4 tank of petrol. It seems to smell of gas when it changes from petrol to LPG. I had it installed a little over a year ago and than I used it for a few months and than decided I prefered to run it on petrol, so I didn't use it for a long time. I had it installed quite a distance away, due to the fact that they had converted a number of the same vehicle and sold them. I could take it back, but I sort of think that this will just increase the amount of money spent on it when I don't even like it.

BRCGB seem to suggest that you deal with the installer.

[Gilbertd]

I generally do not think that LPG is very good.

If the system is correctly specced for the car, installed and set up properly the only difference between running on LPG and running on petrol is that fuel costs around half as much. Personally I detest diesels so they aren't an option and would not go back to running a car on petrol ever again. You've had a bad experience so are going to be biased but it should not cut back to petrol under acceleration, it should not smell of gas and unless you are doing ridiculously short journeys it should not use 25% petrol. You should not be able to detect which fuel you are running on other than by looking at the LPG switch to see that it has switched. Come to that, you shouldn't even be able to tell when it switches over, it should be seamless.

All of the things that you mention are because there is a problem with your install, LPG is a hydrocarbon fuel just as petrol is. The difference is your petrol system has been designed and calibrated for your car, your LPG system obviously hasn't been so it isn't working as it could or should.

[Tubbs]

Its a shame that you have had an obviously bad experience with LPG. But all the problems you mention are rectifiyable, and as other posters have mentioned, properly set up the system will run as if it was on petrol, but at half the cost. Its as simple as that. If you dont feel you have trust in the installer then maybe you should think about going elsewhere to get the issues rectified. However the installer shoukdnt really charge you for any rectification as the system should be under warranty for 24 months.
So its just a question of getting it sorted really.

[classicswede]

I generally do not think that LPG is very good. When it was first installed it operated pretty badly, in terms of cutting out under acceleration. I never quite understood why they would complete the installation with bad settings and than change the settings after 1000 miles so that it does that only when there is less than 1/2 a tank of LPG. I also think that the savings of LPG are not all that great, as to use a tank of LPG requires the use of 1/4 tank of petrol. It seems to smell of gas when it changes from petrol to LPG. I had it installed a little over a year ago and than I used it for a few months and than decided I prefered to run it on petrol, so I didn't use it for a long time. I had it installed quite a distance away, due to the fact that they had converted a number of the same vehicle and sold them. I could take it back, but I sort of think that this will just increase the amount of money spent on it when I don't even like it.

BRCGB seem to suggest that you deal with the installer.

LPG is great but you have had a bad experiance. It is a real shame when installers let customers down like this and the savings are there when the system works as it is supposed to.

A customer of mine ended up having another one of his cars converted by a local BRC installer and had a lot of trouble with it. BRCGB did keep pushing him back to his original installer and it took a lot of return visits to get the system to work at all. I strongly sugest you push BRCGB to help resolve the issue. Call then everyday, twice a day if need be untill something is done. Where abouts are you?