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LPG and snorkels

Posted: Tue Jan 22, 2008 12:05 pm
by Bubba
Now this may sound unlikely but i swear it's true.

Background; I have a 85 FJ70 3F, duel fuel LPG, all fairly stock

Soon after getting it I installed a Airflow Snorkel and this was when the fun started.

Issue; When the wind blows down the snorkel it cuts the motor out, sometimes causing it to stall. It's like the friggin wind blows out the pilot light. It mainly happens when idling but will also kill the revs when driving at top speed and struck buy a gust of wind.

Every time I mention it to somebody they look at me like I was a dim witted red-headed step child that just slipped in some dog shit. For this reason I have withheld posting on here about it.

Question; Is this a issue that has happened to others? What do you suggest as a solution,

I was thinking another filter to restrict air flow a bit more but where would I put it that isn't going to suck water up when I go swimming, maybe a pod filter to replace the hat?

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 12:14 pm
by turoa
your problem is that.......... you are missing 2 cylinders Image

But other than that I still have no idea :?:

You can get prefilters which replace the snorkel hat, or I have seen filters which slide over the hat?

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 12:33 pm
by wjw
turoa wrote:your problem is that.......... you are missing 2 cylinders Image

But other than that I still have no idea :?:

You can get prefilters which replace the snorkel hat, or I have seen filters which slide over the hat?


Why not just spin the hat round 180 degrees?

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 1:00 pm
by Bubba
wjw wrote:Why not just spin the hat round 180 degrees?


Done that, but that only helps when you are driving into the wind

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 1:01 pm
by timotheus
Unifilter 'snorkel sock'.
Can get them off tardme so every now and then.

Id be turning the hat round first though.

Tim.

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 1:43 pm
by rowinz
It nothing to do with the direction the hat is pointing.
One side of the LPG regulator has a vent to atmosphere. Wind across the snorkel hat slightly changes the pressure on the air inlet side, where the LPG is injected. The regulator can't cope with the pressure difference and alters the LPG flow, hence it runs rough then stalls.
Fix is to find the vent, and pipe it to inside the airbox or the snorkel.

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 1:54 pm
by Bubba
legend, pure legend

And despite what all those other guys down south say about you, you are a bloody good bloke! LOL

Seriously, thanks

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 2:20 pm
by niblik
mate of mine runs lpg on his v8 rover in a lux and he notices a power change whether from highway cruising to driving offroad.. from what he sai it can be affected by the tune etc too.. ie no airflow being rammed down snorkel etc..

best talk to some professionals about that perhaps?

just something to take into consideration..

:)

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 2:32 pm
by Bubba
I have been to the pro's. One thing they did say was that it is a old system and that it was designed for motors under 2.5 and that if I spend some $$ I can get a system that will make it go better than any petrol and would compete with a small 8.

but for two and a half K I would rather listen to a 8

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 4:47 pm
by rokhound
Had the same problem with a brand new '85 falcon the old man bought. It had some form of forced air induction, and would occasionally run like total dog shit.

What about putting a donaldson precleaner on top of the snorkle as opposed to the snorkel hat? BNT had them for about $35 just before xmas from memory.

Re: LPG and snorkels

Posted: Tue Jan 22, 2008 5:16 pm
by Jerry
What about a blanking plate for the snorkle for city driving with an engine bay ie normal input and take it off when you go offroad blanking the engine inlet? have a look at the mod Cloggy has done....

Re: LPG and snorkels

Posted: Sat Feb 02, 2008 1:43 pm
by Dr_PC
Is it the same when you go to drive off from a standing start, ie runs rouhg or tries to stall, if so fit a bigger feed line from the tank to the reg

Re: LPG and snorkels

Posted: Sat Feb 02, 2008 2:11 pm
by Bubba
Dr_PC wrote:Is it the same when you go to drive off from a standing start, ie runs rouhg or tries to stall, if so fit a bigger feed line from the tank to the reg


Can't say I have noticed that, foot flat and it's a bit starved, apart from that, not really.

The other issue is when you are slowing down, sometimes it will stalls, but I just crash start it as usually its still moving forward but can be a bit uncomfortable for and unwitting passengers if I happen to select a gear thats a bit low, ie; they nearly face plant the windscreen

Re: LPG and snorkels

Posted: Sat Feb 02, 2008 7:52 pm
by rowinz
Bubba wrote:The other issue is when you are slowing down, sometimes it will stalls, but I just crash start it as usually its still moving forward but can be a bit uncomfortable for and unwitting passengers if I happen to select a gear thats a bit low, ie; they nearly face plant the windscreen


my LPG 3F had the same problem, stalling when engine revs dropped (ie changing down). I controlled it via the hand throttle. I assumed this was a carburetor adjustment thing, having slow idle set too low or something. Didn’t get round to tuning it properly before i sold it.

Re: LPG and snorkels

Posted: Sun Feb 03, 2008 8:56 pm
by Terry
Hi,
late reply, but... had exactly the same problem with my Patrol - a good gust of wind would "blow out" the engine - could happen when idling, or at 120ks on the motorway (in Welly) {bloody embarrasing, actually} - didn't matter which way round the snorkle was pointed. Several "experts" said the same thing as you've already been told- it's the vent on the back of the LPG regulator that tells it what the local air pressure is. Their advice was that I had to put up with it if I wanted a snorkle. Total bullocks. It's just a hole leading to a diaphragm, the assumption is that the air pressure going into the engine is pretty much the same as the ambient pressure under the bonnet. The garage that does my LPG warrants explained it to me and showed me the hole, said he could fix it for a price, or I could do it myself easy. I tapped a brass fitting into the hole and fed it into the aircleaner via a bit of stub pipe welded on and some heater hose. Now the LPG regulator "sees" exactly the pressure actually being fed to the engine. Problem instantly solved. And, with a bit of luck, it's a little more river-proof now.

Re: LPG and snorkels

Posted: Mon Feb 04, 2008 7:22 am
by Bubba
Thanks guys, my kids have a games called "how embarrassing was that Dad?" Every time the motor stalls they ask, and I rate the embarrassing factor on a scale :oops:

Maybe now i can get it sorted