Car LPG Airbox

[Volvi]

Some advice sought from those familiar with cars running on LPG especially the Ford variety.

LPG sometimes backfires and makes a mess of the airbox covers, by cracking them. I got a replacement which came off a Tickford car.

My old box has a hose going into the upper portion of the box, not the main air intake. as can be seen in pics. The newer box doesnt have this hose inlet as the older one no doubt was drilled into by LPG installers.

I dont know the function of this hose but suspiciously it tends to leave oily residue in the upper portion of airbod which is already past the paper filter to air intake areas to injectors. Im a novice at all this so I could be wrong on some a/m info.

So question is what is the purpose of this hose (about 1/2" diameter) and should I drill a new hole for it in same position on newer airbox.

Any assistance appreciated.

Some pics, older upper box has hole on side, newer box lower section has springs to allow non damage in any backfiring.
   
   
   

[Busdriver]

When I had an LPG powered car, the lid for the airbox was secured with springs. when the engine back fired, there was enough give in the springs for the resultant pressure to escape without damaginging the airbox.

If the old box had some hose from the lpg system going into the airbox I'd refit it. (my opinion anyway)

I also found my car back fired when the ignition leads got old, or dirty, or one broke down. If the connects on the ends of the leads are a bit sus, or the resistance in the lead is too high, the spark travelling along the lead can sometimes find an easier path to jump across to another lead. If the cylinder at the end of this lead is on the fueling stroke, BANG. Have a look at the leads and the connectors on the ends.

Also, lift the bonnet in the dark(in your garage) with the motor running. You might be amzed at what you may see.

[Volvi]

Its the breather tube from rocker and needs the cleaner air past the filter. aint it great with so much assistance lol.

[NEMESIS]

Gas...

Is for BBQ's

Not for cars.


Unless the motor is SPECIFICALLY built for it.
Its not that good.

[ROD]

Its the breather tube from rocker and needs the cleaner air past the filter. aint it great with so much assistance lol.

After 10 years you have not realised this is a Bike forum

Sorry dont no much about Gas but i would do as Les said and put car in garage at night with no lights great for finding sparks that should not be there

[ohdear]

LPG versus Petrol
One's for Snags the others for Drags

[NEMESIS]

LPG versus Petrol
One's for Snags the others for Drags

I like that lol

Il keep it for the next sucker who loves gas systems
in there cars

[Mark_S]

Hi first post and I will post a newbie post soon.

I am sure the hose is a vacum to the LPG convertor. Mine sits on the intake snorkle. I will take some photo's latter.

I am not sure what model Falcon you have and how many k's are on the clock.

Biggest cause of backfire is ignition system.

Plugs need to be changed every 20,000 k's (they also need to be gapped at .8 in place or the normal 1.1).

Leads every 50 - 60,000 k's and if you have either a EF or an AU Falcon I would suggest the coil pack need to be replaced as well. I picked a new coil pack up for my EF for around 80 bucks on ebay (brand new) They should be done every 150,000 k's and are a bitch to replace.

O2 sensor is also a good idea to replace as well, around 70 bucks from Bunsons if they have those in Melbourne and around 120 from Repco (don't bother with Ford as your look at $200 +) These take around 2 minutes to replace.

I have also had my airbox modified when the install was done and how a blow valve.

Hope this helps.


Oh one other thing. I post over at Ford Forums and there are some guns with LPG and always willing to help.

CLICK HERE FORD FORUMS LPG SECTION

Cheers
Mark