Log in

View Full Version : very weird gas problem



disco97
3rd February 2010, 07:06 PM
Hi Guys
i have a 3.9 auto which was put on gas july last year in the last month or so its been doing some weird things.

few tech things
leads under a year old 8mm champions (i think)
plugs changes also at same time ngk 5bpes?? (the ones everyone recommends)
89ltr lpg tank :eek:

now the problem
first i had done 250kms then it had no puff so i went to a servo and it opnly took 47ltrs of lpg thought thats strange but milage was about right for the litres put in.

next time 220km and same thing 42ltrs of lpg
so i cleaned the dizzy cap and button (which are all lucas)

then came a 90km one 19ltrs to fill
and no puff to even drive

next one 200ish km and same thing and 50litres to fill it

now when this problem happens i cant touch the accelorator or it just feels like its bogging down but soon as i fill the tank its fine.

i cant see why i have this happening as theres plenty of gas left in the tank but no go.

i took it in for a tune and oil change and go to pick it up and NOT TUNED but charged for oil and filter change of $220 :eek::eek::eek:. when we spoker to him he just says no time blah blah and when pressed on the issue he doesnt know whats causing it.

alos how much do you guys get out of your tanks for there size eg:60ltr tank you can empty it and it takes how much to fill??


thanks
jeff

350RRC
3rd February 2010, 07:50 PM
Hi Jeff,

You don't mention what sort of system it is. That would help. How much gas could you put in it when you got the installation?

Don't know how you'd fit a 89l tank in the rear of a Disco. I've had 2 different 80l tanks in the back of my RRC, one laterally behind the back seat and the current one which only just fits longitudinally. Have seen a 100l tank in the rear of a RRC but there wasn't much room for anything else.

Your first couple of mileage figures are OK.

It sounds like you have a convertor and there is a problem with gas delivery, rather than an ignition prob. If you have a convertor is it iced up when you run 'out of puff' with plenty of gas left?

If so you are short of coolant and / or have an airlock in your cooling system.

cheers, DL

fraser130
3rd February 2010, 07:58 PM
If so you are short of coolant and / or have an airlock in your cooling system.

cheers, DL

I've seen installers plumb in the converter so that there is no water flow through it unless the heater is on!

next time it happens, try turning the heating on full, and if the heating doesn't heat as it should, or it fixes the problem, then the heating water for the converter needs plumbed a different way.

Let me know how you get on and I'll go into more detail if need be....

Fraser

tracker
3rd February 2010, 08:05 PM
Hi Jeff,

You don't mention what sort of system it is. That would help. How much gas could you put in it when you got the installation?

Don't know how you'd fit a 89l tank in the rear of a Disco. I've had 2 different 80l tanks in the back of my RRC, one laterally behind the back seat and the current one which only just fits longitudinally. Have seen a 100l tank in the rear of a RRC but there wasn't much room for anything else.

Your first couple of mileage figures are OK.

It sounds like you have a convertor and there is a problem with gas delivery, rather than an ignition prob. If you have a convertor is it iced up when you run 'out of puff' with plenty of gas left?

If so you are short of coolant and / or have an airlock in your cooling system.

cheers, DL

HI, I had a look at this system today.It seems to lose pressure at a half full tank.Converter is plumbed correctly and quite hot when running.To me there seems to be a blockage somewhere between the gas tank and the converter.But not sure where.Is a inline filter fitted to lpg systems?? Brian
ps it is a big tank that justs fits with the puppy seats removed

Hotdog
3rd February 2010, 08:17 PM
If its a vapor injected system I have heard of blocked filters being an issue with newer installations. After all the gunk from the new tank etc is filtered the blockages become less of an issue and the filters last longer. I have an earlier system with an 80l (water capacity) tank and get approx 300 klms before putting 60 odd liters of gas into it. Yeah i get around 20l/100k's from my D1 3.5 V8,

Cheers

Hotdog

fraser130
3rd February 2010, 08:18 PM
It's most likely a converter problem, or a loose connection at the tank for the electric safety valve. Converters are a really simple device, so not a lot can go wrong.
I would suggest taking the car back to the installer and asking them to rectify the fault.

400HPONGAS
3rd February 2010, 11:38 PM
So 250 on 47 = 5K/l
220 on 42 = 5K/l
90 on 19 = 5k/l
200 on40 =5k/l
Well close enough anyway
60 litre tank , probably only squeezes in 50 litres on a cold morning at best .
You been running out of GAS !!! Try filling it up when it gets to half tank .The vapor pressure problem . you may have a Pickup filter problem or a dicky "excess flow valve" in your tank , check the manual shut off valve is fully open . Is it a vapour injection system or a fumigated system ?

disco97
4th February 2010, 05:06 AM
ok a few things yes its a vapour system.

where exactly is the filter and is it easy to check?

at most i have put in the tank when it read empty but still had some gas in it i could get 72ltrs in it just after install now lucky to be able to put 50ltrs in the system so it aint running out of gas.

i checked the manual valve first and again yesterday wide open

i suppect its a filter problem too but when we mentioned this to the installer i have never seen a blanker look and he said "nah if its a filter it wouldnt run at all "

it will be going to him again but i go away on sunday night and just wanted to see if i could quickly fix it before i went no big problem petrol still runs fine.

400hpongas i have never run out of gas in the times this has happened it is still half full tank at least

tank is 1100mm long and bloody round i wanted more kms before i had to fill up seeing on most trips gas stations are around 400km apart up north


also i thought it maybe the gas from the servo i use so have filled up at 3 different ones


thanks very much for the help guys

400HPONGAS
4th February 2010, 08:42 AM
The symptoms you describe point to the fact , that you are "running out of gas"
I would run it down as low as you can on gas , until it starts to cut out then check the pressures all the way back to the tank .Check the voltages at the solenoid when the fault is occuring .What brand tank , the make model number , and its pickup orientation angle . The service valve has many functions , the Excess flow valve , the pickup tube with a bag filter on the end,the solenoid valve,the manual control valve , any of which could be causing your issue . Obviously check pressure flow either side of the Lockoff solenoid and the filter inside the lock-off solenoid .
If you cant do these things , then take it back to whomever installed it and tell them to FIX it .

p38arover
4th February 2010, 08:59 AM
Are you certain it's an 89 litre tank?

If so, is that water capacity (WC)? To find the LPG capacity, multiply the WC by 0.8 -- an 89 litre WC tank would have an LPG capacity of 71 litres -- which is what you got in when installed.

Has anyone removed/refiited the tank and not done so correctly. If the tank has been rotated in the cradle, the float valve might be shutting off early.

bee utey
4th February 2010, 09:46 AM
ok a few things yes its a vapour system.

where exactly is the filter and is it easy to check?

at most i have put in the tank when it read empty but still had some gas in it i could get 72ltrs in it just after install now lucky to be able to put 50ltrs in the system so it aint running out of gas.

i checked the manual valve first and again yesterday wide open

i suppect its a filter problem too but when we mentioned this to the installer i have never seen a blanker look and he said "nah if its a filter it wouldnt run at all "

it will be going to him again but i go away on sunday night and just wanted to see if i could quickly fix it before i went no big problem petrol still runs fine.

400hpongas i have never run out of gas in the times this has happened it is still half full tank at least

tank is 1100mm long and bloody round i wanted more kms before i had to fill up seeing on most trips gas stations are around 400km apart up north


also i thought it maybe the gas from the servo i use so have filled up at 3 different ones


thanks very much for the help guys

OK your tank should hold 71 litres, 72 is within tolerance. It is unlikely to be the filter as it goes well when full.

The tank could have a broken/bent pick up pipe. Then it would be picking up vapour. Run your car as far as you can, if it's that then you will find the whole tank starting to chill.

It is more likely that the "excess flow valve" in the tank's outlet is tripping. The most common time for this to happen is when you have parked the car over a patch of sun heated bitumen. Then when you come back the car later the heat has driven the gas in the pipe under the car back into the tank (against the spring loaded electric valve). After a while the pipe cools. The tank is then hotter than under the car. When you fire up the car the gas rushes forwards, tripping the excess flow valve at the tank. It makes a little "clang" noise when it trips. This will reset after a while if you turn on the ignition, pause 5 secs, turn off, pause 5 secs, turn on again. When you don't hear the excess flow valve trip it is ready to fly.

In 1994 LPG tanks had to be fitted with electric shut off valves at the tank, before that the excess flow valve was the sole safety item. I was plagued by heaps of sensitive excess flow valves tripping in hot weather. I then started to close down the manual valves, then open them 1/4 to 1/2 turn only. If this proved to allow full power without tripping the excess flow valve then I could hand back the car.Most APA and Manchester tanks (Aust made) no longer have this problem, but imported stuff, e.g Sprint can still be like that.

Also your plugs are standard petrol setting plugs, I have had heaps of people here who have back fired when doing heavy towing or hill climbing: they run too hot. I use and strongly recommend Bosch plugs part no. WR7DC+, gap 0.8mm as out of the box.

A good picture of the inside of your gas tank control box would help diagnosis.

Tank
4th February 2010, 10:31 AM
Might seem silly, but check that the Tank is installed right side up, I had similar problems with a courier vehicle I owned, it had been in a rear end prang and when I got it back from the Panelbeaters I noticed they had reinstalled the tank upside down, regards Frank.

Tombie
4th February 2010, 10:33 AM
Never heard of a D1 with 89L...

Wheres the tank(s) fitted? I think your closer with your 40 something litre capacity.

bee utey
4th February 2010, 10:48 AM
It's easy, 1100 mm long tank, 340 mm diameter, W.C. 89L, takes up most of the luggage space. Easiest but not cleverest!!

disco97
4th February 2010, 10:49 AM
ok i have a 72ltr usable tank and i cant use more than 40lt

i will look into the excess float valve cause it is mainly in the afternoon when i leave work.
THANK YOU BEE UTEY sounds exactly whats happening

i went the 89ltr WC cause then i can go from servo to servo up around cairns seems most servos are 400km between filling stations :) i can always go the scuba later if i needed it the tanks the cheap part

its a manchester tank

bee utey
4th February 2010, 11:32 AM
Sounds very much like its the answer. Just close down your manual tap gently finger tight, then open it 1/4 turn before you start up next. Test drive and open to 1/2 turn if needed.

When your tank is 1/2 full or less the top of the tank is full of vapour at high pressure pushing the liquid flow out. When full there is more liquid to soak up the heat.

Also you can try covering the tank with one of those foil window shades.

If you ever want more gas, I have a pic here of a twin tank set-up I put into a D2, the owner gets 120L to a fill and they are 310 diameter tanks.

disco97
4th February 2010, 12:00 PM
haha nah def dont need more gas 400km+ is good enough
i will try your trick. i do remember sometimes hearing a loader click than normal

disco97
5th February 2010, 08:22 AM
a pic of the setup
plenty of room left :D

i have now turned the valve to 1/4 turn and it runs the same open at 1/4 plus i have now put a tarp over the top of the tank if this helps i will make a box for it.

bee utey
5th February 2010, 12:30 PM
Aah, I think this is one of the imported Manchester tanks, they ran out of production line capacity when the rebate hit. The valves should be locally made Sidek brand, they should have 2 years warranty but if your fix works its all OK anyway.

disco97
5th February 2010, 08:57 PM
so far so good but its early yet. i just replaced spark plugs to day with the bosch ones you suggested and it seems to like them, as well we put the timing abit more btdc. thanks for your help bee utey. oh and the valves are sidek.

doing over 1000km on sunday so will that will tell me if its fixed.



thanks again
jeff

disco97
19th February 2010, 04:51 PM
thank you Bee Utey that seems to have fixed my problems i can now use 75ltrs of gas again before running out. im making a box for the tank this weekend so hopefully that wont make the problem come back :D. i also put the bosch spark plugs in and they do make it run colder about 3-5degrees on gas. i pulled a few leads off and the metal ends came off :mad: so instead of fixing them i just bought new ones but could only get top gun spiral ones on a saturday arvo (will be buying a better set asap).
thank you again bee utey.


cheers
jeff