Hey,

Ive been having a strange problem with my car recently. Its running a dual fuel Vialle system. Now, the problem is when you let go of the accelerator, and brake the rpm dropes drastically, almost stalling the car. When you break lightly, then its not as bad, although there is still something wrong.

However, on sharp braking, and even when turning into/out of a streat (doesnt even have to be a sharp turn), once again the car almost stalls. It looses power steering for a split second (can tell because steering goes hard), and when you go to accelerate from the turn, there is a second or two, where the car is still about to stall then all of a suden its jumps about 4-500 rpm and all is fine, hind of snaps back, and drives off.

There is also a rough idle on gas. Also, under heavy load, the car backfires rather violently. Under light, moderate load its ok. (Im going to be changing the leads soon, currently have Top Gun, i know...crap. Any better recommendations?)


So....any ideas as to what may be causing these problems. Its pretty dangerous at intersections and turns when the car almost stalls. It has stalled a few times already, under heavy braking and taking a sharp turn, lucky there was no oncomming traffic..

Anyone got any ideas?

Im thinking, that it might be the ISC thats playing up...

Dont know about the backfiring under load tho?? Fuel mixture is too lean?

Idle mixtures are too low.
the system should have an idle mixture screw, try adjusting that and see how it goes.
On my EF when it had the old LPG system, i had the exact same problem.

Theres the problem, with the vialle system there is no such thing. Its all controlled by its own computer. Its ment to read off a sensor in the cat, and when i checked that sensor all seemed fine, showing the mixture was between lean and rich...like it should be

Any other ideas?

hey mate
had the same thing happen to me... a quick fix maybe to take the air intake snorkal off and give that a try. reduces the amount of rammed air the car is forced to take in.... car only sucks wat it wants... (so im told) it worked for me, maybe give that a try

Hi slodki
Does your system have the plastic balance hose between the convertor and the air box?
Station-rat

Hi xrsix,

I changed to a tickford snorkel ages ago, and there wasnt any problem for a while, prob close to a year. Until now..Ill still give it a try tho..

Station-rat ,

Yea, there is a 1-1.5 inch diameter plastice tube that runs from converter to bottom of airbox...can it be that?

DUDE!!!! my ed fairmont has the exact same b**ch problem where it stalls taking a turn or gets close to, doesnt drop the revs when you turn to the left as much to.
I aint noticed my car doin the stall thing during braking, but let us know when the problem is found, my mechanic has had a coup of goes fixing it and failed

Ok i will say it again guys listen up,

TAKE IT TO GET TUNED

Take your car down to your local shop that has a got a dyno machine and a gas mechanic. If u live in VIC there is a good one that i use to do mine, Hallam Performance Centre, it costs me around $50 each time (plus u get a power run ) it ususally only take around 30-45 mins for em to tune it and it runs HEAPS better.

Just to give yas an idea of how much it improves, atm there is a 1 rwkw difference between running it on PULP and LPG, roughly i get around 550-600 kms per tank (82L) so it deffintly is worth it. If they cant tune it up, they should be able to twll you what is wrong with it

Where abouts in Vic is this place? $50 for a tune and a power run sounds pretty good...

I still want to see if theres any other things that could solve this tho...dont want to waste money at the mechanics if it aint too hard to do it myself..

while sitting still on a piece of dry bitumen, spin the wheel quickly (ie fast) in both directions. If it shudders or the rpm drop lower than normal, then it may be a faulty power steering switch.

Well as people are saying the mixtures are too lean so they will be able to help ya out there.

Hallam Performance Exhaust
8 David Lee Rd Hallam 3803 (03) 9702 3030


I am in no way affilated with this business just praising their EXCELLENT work

If its been running fine for a while I would bet money it is a balance line problem or you have blown a vaccum hose off when it backfired.Change the leads,look for a air leak and check the balance line.Once all that is done,check the mixtures.

I was under the impression that you cant tune the Vialle system for the air/fuel mixture, because its all controlled by the comp?? Unless you change somethig in the comp?

Which vacum hoses in particular mate? When the car is on, and i listen there seems to be a hissing comming from the front of the dash, near the window, in the middle...dunno if that can mean anything or not??

If the plastic balance hose is split it will give you the exact problem that you are describing. you can buy the hose at Bunnings or Ford sell an update aluminum spiral wraped hose
Station-rat