lpg issues

[bad_religion_au]

my 40 is dual fuel, and wont start first thing in the morning on lpg, once i get some form of fuel down it;s gullet (petrol, rp7 whatever) it starts and runs fine.

anyone out there know what the problem is?

[adam.s]

Mines usually the opposite, starts everytime on gas cause it's already a "gas", when starting on petrol, the engine needs to warm up a bit before it runs smooth.

Do you have any fuel in the fuel bowl when you are trying to start it on gas ?

IIRC, you are meant to clear the fuel bowl first before trying to start/operate it on gas.

[dwaynes]

my gq is dual fuel and i have the same problem

after 4-5 goes of trying to start with gas it finally gets going but is farkin annoying

[V8Patrol]

LPG is the "same" as petrol in that its either too lean or too rich ......
especially in a cold start situation.

QUESTIONS:

Is a "Primer button" fitted ?...... a primer button acts like a "choke" and adds extra fuel to help cold starts.

Is the primer button working ? I've seen a few of these disconected either accidently or on purpose.....
NB: some primer buttons are non existant but may be wired through the starter motor solinoid. A simple way to find if you have a "primer " is to look for a second lockout valve on the converter ( the converter is the thing with the heater hoses conected to it for those that need that book .....
"LPG for DUMMIES"
That 2nd lockout valve should have a small rubber hose from it leading to either the carby base or inlet manifold.


When was the last time the CONVERTER was serviced ?. Every few years or so ( around 5 - 8 ish ) the converter will need a service, whats involved is a stripdown and a cleaning out of the "WAX" build up that forms between the diaphram and body of the converter, this build up stops the diaphram from working correctly resulting in a lean or rich mix and subsequent "hard to start" situation.
NB: The wax isnt a problem once the converted is heated up ( ovbiously the wax melts ! ) but may lead to sluggish performance or even greater and more costly engine damage later on if left untouched.
NB/2: The wax issue is more of a problem in "colder climates" and may require more frequent converter servicing IE every 3 years or so.

Does the rig run ok once its fired up ? ( be it either on petrol or LPG )
A poor starting engine may need some TLC in the form of new sparkplugs/points/condensor/leads etc etc

Other problems may also be apparent to a "qualified LPG mechanic" and may require "specilaised" work ....like fitting a new diaphram ! WOW !

Kingy

[pcman]

my 40 starts ok on lpg most mornings but if i just jump in and turn the key it wont start for 5-10 seconds of cranking

i usually turn the key on for 5-10 seconbds then crank it over starts first go 90% of the time

[ratboy]

it all depends on what system u r running for fault finding
eg / imco / sprint gas / car gas / landi /etc etc
could just be spark plugs ???

[bad_religion_au]

ok, generally it is on gas when i park it. so the bowl is empty of petrol.

yes it has a primer button, it appears to work, but does not make it start...

as for servicing the converter, well i didn't know i had to, that could be next in line. do i need to take it to a "speciallist" to service, or can i pull it apart myself, clean it, new diaphram or whatever, and chuck it back together. sounds like it could be an avenue to pursue, as i've had the truck 3 years and never serviced it, and don't think the previous owner had at all.

i seem to have plenty of spark, and as soon as fuel goes in (be it from a jerry can or a squirt of rp7 or starter fluid) it fires immediately

once started it runs well on petrol, with one flat spot in the mid range, but runs perfectly on lpg

[Gribble]

Make sure your converter to mixer hose is on correctly and tight with no leaks at all. One pinhole in them and it will run shit.

What system of converter/mixer are you running?

[ratboy]

start at the easy bit i would replace plugs as spark can look good but it is no good
from what u r saying go the plugs first then fuel ratio
would like to know what convertor u r running
but just see how u go with new plugs


when cranking engine check that u have 12v at gas lock of while cranking

[360 scout]

depending on how your lpg system is wired ,the primer will only release gas while the engine is cranking. it has to do with the safety only opening the soleniods when the ignition coil is fireing it also helps if you give the carb some throttle when cranking because opening the butterflys helps suck the lpg in quicker!
Hope this helps

[bad_religion_au]

thanks guys, will scrape the mud off the converter and try to ID it tomorrow, got some headlight wiring to track down too...

as for the starting tips, thanks, it was starting fine with all the above mentioned methods (primer while cranking, open the throttle etc) untill last week.

[outlandy]

Hey Mate
I have the same problem in my cruiser. It just means you have a little leak between the two lock off valves and it is taking time to get to the converter and it has air in it aswell by the time it does get there.
I fixed the problem by throwing the whole system out and running on petrol only as it costs roughly the same to run on gas or pet.

[pcman]

yo gotta be joking the same costs on petrol and lpg

so 18l per 100km on lpg so about $9 per 100km
or 18l per 100km on petrol so about $18-$19 per 100km

drive 1000 kays and ive already saved 100bux

i know on petrol mine gets no where near that i use about 30l per 100km so im saving atleast 20bux per 100km on lpg

[outlandy]

Mate if you can get the same fuel consuption on gas as petrol I want to meet you gas mechanic as I use just ove double the amount of gas as pet

[outlandy]

Mate if you can get the same fuel consuption on gas as petrol I want to meet your gas mechanic as I use just over double the amount of gas as pet

[Shorty40]

I just converted my GQ from petrol to straight gas and I am only using about 5 - 10% more gas than petrol. So, it will work out heaps cheaper to run

Also, my system takes about 5 seconds of cranking before it starts. But it will start 1st go, everytime.

I would have your system looked at before throwing it out

[outlandy]

Straight gas is different.
I have straight gas on my commodore and I love it. It is as cheap to run as my new astra and it is a V8, but dual fuel is sucking people in because they are paying less when they visit the pump. They are not realising that they are visiting the pump more frequently

[pcman]

i drove my 40 on petrol for 2 weeks at about 35l per 100km

i said stuff that and fitted the duel fuel system back into it
was using about 25l of lpg per 100km

then i decided to get rid of the petrol and went straight lpg and im now using 18l of lpg per 100km

so im damn happy with that

average price of lpg is 40cpl so it costs me about 6-7bux per 100km

i drove melbourne to euroa which is 180km for $15 with all my camping gear


and theres no gas mechanic i do everything diy im just skilled

[outlandy]

I had better get you around to tune my cruiser as I get about 25-35L per 100kays on gas and about 14-16L on pet. The price of gas is around 40-50 cpl and pet is around 95-105 cpl. I cannot see the point in paying the 1500 bucks for the conversion. Especially when the tank fouls when I go off road and I have been hard pressed to get a jerry can full of gas when I run out in the bush!
Gas Sucks on 4wd's

[RaginRover]

I had better get you around to tune my cruiser as I get about 25-35L per 100kays on gas and about 14-16L on pet. The price of gas is around 40-50 cpl and pet is around 95-105 cpl. I cannot see the point in paying the 1500 bucks for the conversion. Especially when the tank fouls when I go off road and I have been hard pressed to get a jerry can full of gas when I run out in the bush!
Gas Sucks on 4wd's

You just need to be more creative.

I have dual fuel and it is great, 25L/100K in heavy traffic 5 days a week
about 17/100K on the highway, I need to tune it up a bit more, advance her up.

Tom

[chimpboy]

I had better get you around to tune my cruiser as I get about 25-35L per 100kays on gas and about 14-16L on pet. The price of gas is around 40-50 cpl and pet is around 95-105 cpl. I cannot see the point in paying the 1500 bucks for the conversion. Especially when the tank fouls when I go off road and I have been hard pressed to get a jerry can full of gas when I run out in the bush!
Gas Sucks on 4wd's

Yeah, you had definitely better get someone else to tune up your cruiser because your fuel consumption on LPG shouldn't be anywhere near that much higher than your petrol consumption.

I agree about the jerry can though; that's why dual fuel is preferable over straight gas imho.

[pcman]

you guys need to be more inventive about a gas jerrycan

http://cust.idl.com.au/athol/carbits.html

and also scroll about 1/2 way down

http://www.outerlimits4x4.com/PHP_Modul ... &start=510

[Gribble]

you guys need to be more inventive about a gas jerrycan

http://cust.idl.com.au/athol/carbits.html

and also scroll about 1/2 way down

http://www.outerlimits4x4.com/PHP_Modul ... &start=510

Just remember that if you get caught "decanting" a mobile container into your vehicle container you can be fined about $10,000. If someone catches you of course.

[Loanrangie]

If you have an impco lpg system then hold the loud pedal flat while cranking so the vacumn pulls in some gas.

[skippy's GQ]

for $30 worth of GAS i grt about 300 to 350kms, $30 of petrol and i get just over 220 kms


Sounds like you need it tuned, you cand chang the mixtures on the converter correctly with out a gas analyser.