stalls hot and wont start

Propane, Butane, LPG, GPL, C3H8, C4H10
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crsmiffy
Posts: 22
Joined: Sun Oct 30, 2011 8:28 pm

stalls hot and wont start

Post by crsmiffy »

hey guys, long time no talk.
any way last year my 72 Galaxie did a few backfires on the way home and eventually stalled 15 min away. Wouldn't start again.
Thought it was maybe the dizzy (for various reasons, raced home, came back tried to start it, no go. Did a quick dizzy swap on the side of the road and away it went. It's the dizzy right? Wrong.
Got to mates place, stopped car, wouldn't start.
Went home, came back next day started from cold ok, drove home 2 min away, wouldn't start.
I could almost get it to run with timing but not so much. that isn't it.
start it drive around the block and once home wont start.
Anyway this seem to be the norm now. Ran out of money and lost my job at the time (have one now) so out of rego.
I do need to confirm (it has been a while so I think it works) that it runs on petrol thereby confirming it's the LPG system, it is a dual fuel but has a mech fuel pump but it takes ages to fill up from cold, easier to prime carby through the side port.
Does this sound like something the LPG would do. it is now over 7 years old so maybe a diaphragm could have failed?
thoughts anyone?

storm
Posts: 796
Joined: Wed Jan 10, 2007 10:10 pm
Location: NSW, Australia

Re: stalls hot and wont start

Post by storm »

crsmiffy wrote:thoughts anyone?
Where does one start?
Without going through your old threads what is fitted to the Galaxy? (maybe it would be a good idea if you put this information in your signature so you don't have to type it up more than once).

If the issue is with the LPG system it could be anything from the tank to the mixer or even electrical gremlins rearing their ugly heads cause you fed the mogwai after midnight.
So start from the very beginning and give us more information on what components are fitted to the car, what setting you have the points (is it points or electronic?) and timing (actually check the timing to make sure it is what you tell us it is). Is the filter blocked? are the lockoffs working and clear? is the air cleaner clean? what's the spark like (with the engine both cold and hot)? What condition is the mixer in (are all the parts in good working order)? what condition is the regulator in? (is there possible damage to these parts due to backfiring?)

Don't automatically blame the LPG. Honestly in my time with LPG if I had a $ for everytime someone said the engine won't start it's the LPG system and it was actually a combination of things and the LPG system had nothing to do with it I'd be a rich man. Go through normal testing procedures and make sure absolutely everything else is right as well.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456

bumpstart
Posts: 133
Joined: Wed Jan 20, 2010 9:09 pm

Re: stalls hot and wont start

Post by bumpstart »

sounds very much like an LPG car that has a low level in the coolant system
as such , the LPG will only flow ( as a vapour ) for a short period until the vapouriser freezes over , and the engine then leans out and stalls

given some time the fuel in the vapouriser melts and the engine will eventually restart and drive another short distance before the cycle continues

check there is plenty of coolant and that it is flowing through the vapouriser
when the going is hard, don't retard, remember your lubrication

Steptoe
Posts: 1504
Joined: Fri Feb 02, 2007 8:32 pm
Location: JAFA , New Zealand

Re: stalls hot and wont start

Post by Steptoe »

my thoughts on reading also
Is the converter back freezing up?
And it should be mounted with the top at ot below the water level in the radiator...
or if it is not, then when radiator is filled the car needs to be facing up a hill so the level in the radiator is higher....or the top water hose to the converter cracked to bleed any air lock out... should be routed so water in the bottom out the top.
The other issue could be how its routed in also considering the car heater radiator....ie when the heater water flow is cut off, the flow thru the converter should still be open....turn heater on see if that makes a difference.
My Spelling is Not Incorrect...It's 'Creative'

crsmiffy
Posts: 22
Joined: Sun Oct 30, 2011 8:28 pm

Re: stalls hot and wont start

Post by crsmiffy »

Thanks for the replies people
Car is fitted with Impco 425 and l series convertor. When it went on me, there was an electronic dizzy fitted. It was a fleabay item given to me so trust factor low. I then fitted the original points dizzy and it went (for a little while) as described in the OP. I will get a bashing for this but I don't have a timing light of my own and time it by Feel, ear or what ever you want to call it. I have not tried to get max power (well I have, but not happy with results, another story), but set it so it starts well on LPG and runs pretty good nowhere near pinging even on petrol (even if it runs like a dog on petrol-again another story)
It has been like that for about 4 years since I got the elec dizzy, but only done about 2000kms, and in fact after sitting for 4 months without a battery it only took a couple of goes to start.
Funny you say about the water level as for some reason I noticed the water was low and topped it up a long time ago but it still did it after that. I will check that as it has been sitting a while but if it's losing water that's a complete other problem.
Hosing should not be a problem as it has been working well since I rerouted the hosing when I replaced the heads just after I bought it and plumbed up the same way after I rebuilt the engine and it isn't reliant on the heater working. I haven't looked for a while but I do remember thinking that and made an effort when I hosed it up.
I have considered the lock offs as I had the fuel one fail quite a while back and realise that they can crap out. In saying that I would've thought that they would fail shut/open but electrics are funny things yeah?
Backfiring damage is something to be considered but it has backfired more when I have been trying to sort this then before so if I find that it will need repair but may not be indicative of the problem.
Again something has changed/failed as it has been reliable and only a couple of months before it failed it was my daily driver and started/ran well every day.

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