Siphon stale fuel?

[ghost123uk]

Ooops, note to self = RTFM

RTFM??? You're so down with the kids John! What's RTFM?

It is an acronym for "read the f-ing manual" but amongst us cool blogging hip hop dudes, it has been widened to mean "read what was written"

[timski]

I'm not sure what this means, but it's incorrect. Gasure used to fit an injector piggyback loom and emulator box - complicated, expensive and unnecessary on a Digijet as the ecu doesn't need emulation as it's a bit dumb. All that's needed is to switch off the 12v supply to the injectors when changing over to LPG, which I do with a delay timer (to smooth changeover) relay in the relay box above the coil. I believe Gasure may have now adopted the the same method.

That sounds more like it: a relay above the coil. My description is probably a case of Chinese whispers

[timski]

Hi Guys,

Van is back from the garage. It appears to be running well on GAS and petrol.

I've got a couple of concerns though

1. The MAF sensor had been damaged so needed replacing. The mechanic suggested that might have been caused by a backfire and I did have several backfires in the last few day before I had the issue with the wiring loom so that makes sense. He's replaced it with a Gold MK3 MAF sensor as that is much cheaper. He said many people say that isn't possible but he reckons it is and he's done it and it is running. Any thoughts on that?

2. The petrol pump is very noisy. I can hear it whining from within the van. I wondered what the noise was at first and then traced it back to the pump. It is a cheap after market pump that I sourced from eBay. The original pump was noisy when you first turned the key but once the van was started I couldn't hear it. It was as if it made and noise whilst it was primed but not when running after that. The new one makes the same level of noise constantly. When I switch over to LPG the noise stops. The mechanic said that would be the new clamp and stiff rubbers directing the noise through the floor. He reckons it will die down once the rubbers wear in. Does that sound feasible? If so why would it stop when I switch to LPG? I thought the pump was supposed to run constantly even on LPG as the petrol lubricates the pump (at least that is what I read elsewhere I think).

Thanks,
Tim.

[ajsimmo]

1. You should have a backfire protection valve fitted (aka catflap) betweem AFM (it's not a MAF BTW, they came later). If you have one it doesn't work and needs replacing, and if not you need to get one fitted.
Not sure where you get a Gold MK3 MAF sensor, but it sounds a bargain! Wouldn't fit on a Digijet though.
It is possible to use a Bosch flap type air flow meter from an alternative model of car. I've no data on the differences between them, but I do know a Peugeot 205 Gti 1.9 unit works well. Other candidates are Pug 306, BMW 320, Citroen BX Gti.

2. I don't know who did your conversion, but on Campershack conversions the fuel pump is switched off whilst running on lpg. The switchover relay cuts power to petrol injectors and pump. No need for it to run whilst on gas. Your pump shouldn't be that noisy, but if you run on gas all the time does it really matter that much?

PS For all injection owners, a handy "Did You Know"...
If the petrol pump fails and it won't start you can force start up on gas by switching on ignition, long press on lpg switch button until yellow light comes on solid, then turn key to start.

[Mocki]

assuming its one of them "new fangled" push button switches and not a old skool rocker switch

[ajsimmo]

assuming its one of them "new fangled" push button switches and not a old skool rocker switch

Indeed.
You can do it too with some rocker switches. Ignition on, flick switch quickly to petrol then back to gas, yellow light now on solid, starts on gas!

[timski]

1. You should have a backfire protection valve fitted (aka catflap) betweem AFM (it's not a MAF BTW, they came later). If you have one it doesn't work and needs replacing, and if not you need to get one fitted.
Not sure where you get a Gold MK3 MAF sensor, but it sounds a bargain! Wouldn't fit on a Digijet though.
It is possible to use a Bosch flap type air flow meter from an alternative model of car. I've no data on the differences between them, but I do know a Peugeot 205 Gti 1.9 unit works well. Other candidates are Pug 306, BMW 320, Citroen BX Gti.

Haha, I've just re-read my post. I meant Golf sensor but you probably guessed that already. It was probably an AFM too. Chinese whispers again. My conversion was done about 3 years ago by Elite VW, an agent of Gasure. I don't know whether there was a backfire protection valve fitted. Could successive backfires damage the protection valve and then lead to damage of the sensor. I did have quite a few big backfires over the period of a couple of weeks.

2. I don't know who did your conversion, but on Campershack conversions the fuel pump is switched off whilst running on lpg. The switchover relay cuts power to petrol injectors and pump. No need for it to run whilst on gas. Your pump shouldn't be that noisy, but if you run on gas all the time does it really matter that much?

Elite have just carried out a wiring change so the injectors are switched off using a relay so I'm guessing they do the same for the pump and that probably explains why the pump goes quiet when I switch to LPG. I had read elsewhere that the pump should always run even when on gas as petrol is required to lubricate the pump. I must say that didn't make sense to me at the time I read it. The sound itself doesn't bother me as long as its explained/safe. As you say, I'll run it on gas as much as I can anyway.

PS For all injection owners, a handy "Did You Know"...
If the petrol pump fails and it won't start you can force start up on gas by switching on ignition, long press on lpg switch button until yellow light comes on solid, then turn key to start.

I didn't know that actually. And I do have a new-fangled button would have been handy to know as I was giving the air-intake a squirt of cold start to get it going whilst it wasn't working.

Thanks!
Tim.