LPG Discussion Forum

Well done, your getting somewhere now! Wiring sounds a bit like some of the VW stuff from the same era, goes hard and snaps or the insulation flakes off and shorts out, hopefully you've got that sorted now. No wonder it ran badly and then cut out with only 2 cylinders though.

I've had it running 25 minutes now just at idle all warmed up. I hadn't switched to petrol, I suspect it has a faulty reducer temp probe, the gas temp is at 34 deg C but the reducer temp is reading - 39 deg C, it's nice and warm to the touch so not reading correctly. I suppose I can just switch it manually to gas and see if she runs? I have the change over temp set at 20 deg

Looking closely at the temp probe on the reducer, it has damaged wire right where in goes into the sender. I'll need to replace that

Hmmmm, it won't switch to gas from petrol with the button in the software, it gives a little stutter and then keeps running on petrol. So is this because I am at idle not meeting the change over rpm of 1600 and or the reducer temp showing as negative 39 deg? Is that change over button still subordinate to the limits set in the software?

It will need to see both temp high enough and revs above the level set. You might need to do some basic setup as well, like specify number of cylinders, rpm detect etc. Reducer sensor will be an issue, you might be able to get round it with a resistor of the right value until you get one. Or try to solder wire back on even just as temp fix whole you wait.

Not sure on the emer, but some ecus you can drop the rpm threshold down and it will then switch as soon as its warm enough.

Did the tank come with gas in it? Or have you filled it already? You can sometimes find the first time you try to switch with new kit it dies as it's full of air. That will fix itself with a couple of tries though.

Switch doesn't override the ecu to make it switch to gas. It's there to select between automatically switch to gas or petrol operation. Most of the time you just leave it on the gas setting and let it manage it for you.

Unfortunately the temp sender wire is broken right at the brass fitting so no way to solder it, not enough room. Bugger. Looks like I'll be waiting till I can get one online. Ah well. It's the 10mm jobby to emer with the female super seal plug, Tinley tech have them but they are out of stock. I guess I can try to get a universal one and then solder it onto my plug.
The tank is still half full from the old system, I only took it off the road a bit before Easter. Like you say I'd expect a bit of air in the lines initially that might make it splutter or stall until its all primed up.
I've reset the ECU to factory and started fresh as it still had the old v6 configuration in it's brain. I've been through all the settings and made what I think are the appropriate selections. I just need that damn reducer temp to be able to start fiddling with it properly.

It had the old mixer system and it looks to me as if they cut the signal wire from the coils to the Peel system in the wrong place, twice before they put it on the negative. The one on the temp sender is so far the only thing I've found wrong with the new second hand vapour system, not too bad. Your help has been truly appreciated

A temp reading of -39 degrees is the default for an open circuit, which is exactly what you have with a broken wire. However, if you short the two temp sensor wires together, it will show a very high temperature so should switch over. You'll need to manually switch or it will try to run on LPG as soon as you start it, but it will at least allow you to check it and see how it runs.

rodstares wrote: Fri Apr 17, 2020 5:50 am It had the old mixer system and it looks to me as if they cut the signal wire from the coils to the Peel system in the wrong place, twice before they put it on the negative. The one on the temp sender is so far the only thing I've found wrong with the new second hand vapour system, not too bad. Your help has been truly appreciated

That does make some sort of sense, hopefully you've found all their mistakes now then.

Thanks for the tip Gilbert, I'll see if I can get that to work. It's broken flush with the surface of the brass bit so I may have to jam a screw or something into the wire stubs to get them to connect, cheers

Brian, I'm sending it to the autoelectrician on Monday to have the wiring checked over and all tidied up. It looks a dogs breakfast at the moment.

Gilbertd wrote: Fri Apr 17, 2020 11:22 am A temp reading of -39 degrees is the default for an open circuit, which is exactly what you have with a broken wire. However, if you short the two temp sensor wires together, it will show a very high temperature so should switch over. You'll need to manually switch or it will try to run on LPG as soon as you start it, but it will at least allow you to check it and see how it runs.

Oh, of course just twist the wires together, nothing to do with the brass bit. Sorry, bit slow this morning

Rpm is stuck on 89, 0 with the engine off goes to 89 and doesn't change with the engine running. I have it set for the ECU to read rpm off the injectors, I think I'll hook up the brown wire, or in my case black to the coils pack neg and see what happens. Twisting the wires together for the temp sender has done the trick, it's reading 110 degrees, I just can't get it to see the revs to allow change over. I can lower the set revs for changeover to 0 and try that too I spose

Update! Couldn't get the rpm to read right so I hooked up the brown wire to one of my coils and set the software to the signal type weak and ignition type rpm sensor. It's now reading same as the cars tacho. Runs fine on petrol then switches over to gas runs ok, bit lumpy and won't rev. Initially it was running on gas steadily bit now throws a water temp error whether I have the wires twisted together on the sender or not. Still, it's progress

Could be a few things causing that, given it's used kit start by switching it to gas, then back to petrol, and monitor the gas pressure, ot should stay stable, if it drops you may have a leaky injector or reducer issue.

While the temp sensor wired like that will allow switching at any temp, you want the vapouriser to be kept from freezing so let it warm up a bit before trying to switch it over.

Double check you have the cylinders matched up wiring wise as well, easiest way to do that is to switch cylinders between fuels and see what ones react differently

When you say switch cylinders between fuels do you mean I can individually switch them one at a time in the software?

Yes, you should be able to. Will have a look at software in a bit. Most supports it, not sure if emer does

I see on the diagnosis screen I can switch them on and off individually

When I switch from petrol to lpg the gas pressure drops from 1.06 to 0.96 ish and jumps about say .93 to .99 then when it goes back to petrol it goes back up to 1.05 stable

Interesting, if I shut off all three injectors in one bank or the other it doesn't seem to run any worse than if I have all six running. I can hear them clicking so I can identify each bank easily. Would this tend to indicate poor gas supply? The injector timing runs at about 3.47 for petrol injectors but gas is around 7.5 should they be around the same?