I have an EFII with factory gas fitted and when I have my foot on the accelerator keeping at a specific speed there is this whistling noise which is hard to describe. It only does it when driving, not when it is in PARK or neutral. It seems to come from the accelerator but i am not so sure about this. And it only does it when I have the accelerator slightly depressed, when i push the accelerator further, it doesnt make any noise. I have tried listening under the bonnet while someone puts the car in drive and holds the brake while accelerating but cannot hear anything under the bonnet. You can only hear it from inside. It is very annoying. Anyone have any ideas what it might be? or what i could look for?
It is a tickford factory gas system EFII i6. I only bought it recently and I know the gas converter was replaced about 12 months ago. It is dual fuel, it doesnt make the sound when runnning on petrol.

anyone? no ideas? am i the only one with this problem?

I have the exact same problem, i noticed its from the tank and only does it when its nearly empty, only makes the wissel noise to about 1800-2000rpm then it goes away

I was spining out but i really listened 2 it and found it, dont know if it's a bad thing either?

make sure the gas tap is fully opened on the tank.

thanks guys, I have spent some time on it and can confirm its not from the gas tank. I took a closer look and it seems to be coming from behind the dash cluster. When under the bonnet, very hard to hear due to engine noise but can narrow it to the converter. The funny thing is you can barely here it through the converter, only from inside and its clearest and loudest is from behind the dash area.
What could cause this noise in the dash in relation to the gas system? As i said before, it doesnt do it on petrol. I appreciate all advice.....thanks again!!