LPG tanks and sludge

[beamerguy]

Hi guys, as above, can lpg tanks fill with sludge or anything that can reduce there flow over time?
Basic ive had the tank in question for 5 years now and its veeb swaped from one vehicle to another and shows the same problems on each vehicle i.e. diffrent cars, diffrent lph systems but the same tank. Its a 4 hole tank, the problem is only evident when you floor the pedal and seem to get lack of gas reaching the vapouriser, on the car with the kme system the petrol injectors go full open and it switchs to petrol until you lift off, on the car with the oscar N system the system would switch back to petrol until i set the minimum pressure seting to 0 and now it lacks power after around 4000rpm, its been set to switch to petrol after 4000rpm has a temp fix as it runs fine up to this point, also i find it seems to get worse has the tank contents falls, great when full, @!## when almost empty. The tank gas valve has been checked while it was still on the tank and was clean, could the dip tube or gause be choked up? Mark.

[beamerguy]

Also to add because of the issues it has caused random misfires but only on lpg, no issues on petrol on either car, the cars are hyundai trajet 2.7 v6 with kme diego system and kme silver vapouriser and a 2.5 v6 rover 75 with oscar N system and a magicjet vapouriser, the trajet has recently had new plugs, ht leads and new coils, the rover has had new plugs.

[Brian_H]

I've got one in the workshop that when you pick it up and tilt it sounds like theres a load of iron filings inside it - As yet haven't got round to taking the valve off to have a look whats actually inside it, but its possible.

Have a look at the pressure shown in the software when its playing up and compare it to when its not - Get someone to look at the laptop while you drive is easiest to do so. If its dropping off something must be restricting it.

Is it a cylinder or toroidal tank?

[LairdScooby]

Just a thought here and i could be miles off but could it be rust particles that sound like iron filings? If the tank was ever left open on a damp day then moist air would have got inside. In an ideal world, moisture won't get into a tank but i'm sure it does happen.

[beamerguy]

Its a cylinder tank. Is it possible to tank the valve off and remove the dip tube from inside and make sure its clear?
Mark.

[Gilbertd]

Yes, although it's a good idea to make sure the tank is empty first......

[Brian_H]

Just a thought here and i could be miles off but could it be rust particles that sound like iron filings? If the tank was ever left open on a damp day then moist air would have got inside. In an ideal world, moisture won't get into a tank but i'm sure it does happen.

I'd suspect its bits of fuel pumps etc over the years it was used, part of an ebay purchase about 4 years ago (couple of complete systems removed from cars) that I've never used the tanks from (the tanks were used on necam EGI systems so are probabbly 15 or so years old by now - I need to get rid of them just haven't got round to doing so). Those that have run on Red cylinders report finding lots of bits of metal in them, as under usual use they would never get out of the cylinder.

Also whilst it may not have been left open, everytime you fill you can introduce some water if the coupling isn't dry (one of mine has a bad habbit of filling up with water though think it just collects in the housing then gets ejected when removing the filler gun, though if you drive it without the cap on theres obviously more possibility of getting water into the tank)

[LPGC]

Conversely, on a 4 hole you could remove the outlet solenoid and gauge sender, flush water IN through the outlet and empty out through the sender... Gunge/filings would be pushed away from any pickup strainer and eventually out of the tank. If worried about remaining damp could empty as much water as possible out the tank then heat it to steam/vapour off most of the remaining damp / maybe flush out with a little petrol...

But - this is nothing to do with your piping or other restrictions such as too small a reducer solenoid?

Simon