308 on gas won't start in the morning

[BeRad]

I know its not a toyota, but this is one of, if not the best info forums for engine problems

I have a mate with a carby 308, electronic dizzy + coil, running on gas, in the morning it wont start and just coughs and splutters a little as he cranks it, you can crank it until the battery dies, still won't start.

But, come home in the afternoon, and it starts first turn like nothing has happened, its been happening for the last 2 weeks without fail..

Any thoughts?

My only thought is not enough fuel with the ambient temp being lower/ slightly retarted timing?, although the weather is not cold in the morning in brisbane at the moment, hovering around the 20's.

Thanks again

Brad.

[Radar]

The coolant temp needs to be engine temp for the converter to work...
That's why it works so well in the afternoon when the motors still rather warm.
If its cold the converter wont change the LPG from gas to vapor....

[mick08]

Stick some petrol init and see if it'll start in the morn, that isolates the gas system as the problem, when it does start what is the initial timing? Does it drive nice when it does start or does it pop and bang, what sort of dizzy is it?

[Bananaman]

The coolant temp needs to be engine temp for the converter to work...
That's why it works so well in the afternoon when the motors still rather warm.
If its cold the converter wont change the LPG from gas to vapor....

If it didn't work at all at ambient temperature, then no straight LPG car would ever start and run until it was warm? Speaking from experience, the converter will continue to work (as far as keeping the car running at least, maybe at bad mixtures) until it is well and truly frozen over. I run straight gas on my daily (304) and while it takes more cranking from a cold start, it still runs fine on a cold morning.

[pandaah]

how often does your mate use gas and how often does he use fuel?... if he constantly uses gas could be a gummed up carburettor, which may require cleaning, rekitting...

my advice would also be dropping a touch of fuel down the throat in the morning see if it starts while its in gas mode...

i get it alot at work with efi / gas systems where people hardly ever use fuel, gums up the injectors now the system cant start in the morning cos it uses fuel for initial cranking....

hope that helps!

[BeRad]

It runs 100% on gas and has done for the last few years, the motor never uses fuel, and has never had this problem before.

Timing seems fine, advancing it a tad which should help things has no effect on anything.

With the carby, i have no idea as i've never dealt with a 308 little own one running 100% on gas, so pulling it off and giving it a clean will fix it, rekitting as in what, what breaks etc with running the car constantly on gas?

[pandaah]

im betting thats your problem.. gummed up carburettor, needs cleaning or rekitting... could be wrong but i think thats your problemo

[BeRad]

Yer it would sound like the logical explanation haha, although stranger things have happened, ill let him know.

Thanks

[andrew_mx83]

a bit less ignition timing will make it easier to crank. bigger battery is good with LPG too for higher cranking speed.

is there a primer solenoid on the LPG converter? they can be had cheap from impco/wreckers, just wire it in with the starter circuit for an extra dump of gas into the manifold while cranking. if this gives hot start issues then wire it thru a thermo switch as well. if u want i can take a pic of my converter when i get home.


gas will always be harder to start in the mornings but u can usually get it setup to run pretty right.
the converter will still convert the liquid to gas when cold however not as well. note that the mixture is determined by the temp in the converter (on an impco system at least) so when its cold it will automatically run richer.


if hes desparate to get it started, BEFORE the batttery gets low and crank speed drops u can push the metal button on the bottom of the converter and purge all the gas in it straight up into the mixer. this often works but may sometimes backfire
if its really really cold then pour a kettle over the converter if it has started to ice up.

[andrew_mx83]

also being a 308 is it the shittiest of shitty wines

[Cuzzo]

im betting thats your problem.. gummed up carburettor, needs cleaning or rekitting... could be wrong but i think thats your problemo

Umm wouldnt this not allow it to start fine in the afternoon and run perfectly once the whole engine has risen upto ambient temp?

[dnegative]

Get some new leads and plugs, propane is much harder to ignite compared to petrol. Even harder when cold.

[KENut]

Get some new leads and plugs, propane is much harder to ignite compared to petrol. Even harder when cold.

push the metal button on the bottom of the converter and purge all the gas in it straight up into the mixer.

Also if its running a petrol carby (on staight gas) the gaskets can "dry up" and air leakage can occur

[Grega]

i'm voting primer
is there a switch or something thats pressed at start time to prime it with gas?
that may be cactus

try pressing the metal button in the middle of the convertor and then starting it? any better?

failing that when was the gas system serviced. its possible the little filter in the lockoff valve may be gummed up with crap - worth a clean - i think most run a 5/8 nut on the bottom ; otherwise, off to a gas mech for adjustment perhaps?

[ian]

easiest solution is to tell your mate to take a job that has afternoon shift ,
but apart from that , i had a friend that had an old ambulance with a 351 in it and it was a pig when cold
being an enterprising fellow he hooked up a one way water fitting and had a hose directly from his purge thingy on his hot water system and he used to fill his radiator / mixer with hot water first thing in the morning ,,problem solved
for him anyway