My EF falcon runs Vialle LPG converter and electronics (not factory fitted).

Problems:

Won't idle on LPG when cold.
Very rough idle on petrol - and has intermittent misses on petrol though out the rev range - like it's not getting fuel, even though it is running rich – sometimes has black smoke (unburnt fuel) when trying to idle.

I took it to my mechanic and he checked for vacuum leaks, changed the fuel filter and ran some injector cleaner through it but with only little improvement. He suspects the poor running on petrol is caused by the electronics for the LPG system and can't sort out the idle

I then sent the car into an LPG repairer/installer for them to have a look at, they drained the wax out of the converter, and checked everything was hooked up right, but said they said everything on the LPG side appears to be ok but couldn't do much more until the car was running properly on petrol.

After I left the LPG place the car started stalling on LPG when stopping at traffic lights, or when you are slowing down to turn in a street or round about etc. I phoned the LPG place when i got home and they said get the car running right on petrol and if it continues to stalls on LPG they will look into overhauling or replacing the LPG converter but can't do anything more in the meantime.

I've stopped using the LPG and it killing my pocket on petrol, the trip computers telling me the average fuel consumption is 35 litres to 100km.

It cost's me every time i send it into be looked at and they seem to be making no progress. Should i get an Auto sparky to check it out? What do you guys think.

Find another mechanic !

I would first check the balance pipe is in tact and no leaks, without it, it will stall and not run well.

Have you checked to see what codes the ecu has?

I'd probably guess the oxygen sensor?

Check the output with a multimeter after the engine is warm and see if the voltages are moving.

If it isn't running properly on either fuel, wouldn't they suggest it isnt a fuel issue?

Stationrat is right, find yourself a good mechanic. One that likes fixing cars and doesnt give up easy. This is prob going to get expensive, try and do as much as you can.
Grab a manual and check for codes first.

balance pipe meh, im not running one, runs fine.

but luke111, could be on the money, check the ecu codes, would be a good place to start.

I found out what was causing the car to run like crap on petrol, The fuel pump was dropping dead intermittently, only for about 0.5 of a second at a time.

It got real bad on sunday and then it finally gave up the ghost, I fitted another fuel pump last night and what a diference it now runs a heck of a lot better.

hello i see in another post u have vaille comtrol box do u have a wiring diagram for it i have another set up in my car but its a basic control set up would like to wire the vialle system up to my set up any help would be good

Oxygen sensor is almost certainly stuffed and only $50 to replace yourself. It made a huge difference to my car.

The car is still running like s**t. Think the 2nd fuel pump is about to drop dead and the car also stalls sometimes when you deaccelerate. Quite dangerous if you are trying to turn a corner when it stalls!!!

I think i will replace the oxygen sensor, and am looking at getting the regulator rebuilt or changing to another brand of regulator. Got prices from ford for a new Vialle regulator $3300.00 ex GST or $1300.00 ex GST for an overhaul kit.

Piss the Vialle off mate, they're known for their problems and as you have found out, very expensive to replace/repair!

Fit an OMVL R90E to it, a lot cheaper and far more reliable.

what has the fuel pump got to do with your LPG problems?

If its running crap on both....
They both use the O2 sensor for the mixtures on both the LPG and petrol, that would be where I would start looking

Hi all

This going to sound weird and I probably wouldn’t of believed it if it didn’t happen to me but…when I bought my EF it ran really good on gas. Then one day I noticed that the induction inlet for the air box was all smashed underneath presumably from a broken fanbelt at some stage. I tracked down a good one and then the Gas started running like crap, doing similar things to bottlejacks – engine will stall under braking etc. I never suspected it until my mechanic told me about it and I took the induction snorkel off and went for a spin around the block and sure enough it was OK on gas! My mechanic said that the air box is very restrictive at low air flows and can effect gas metering at low RPM. The holes in my induction snorkel may have been intentional. It will cost you nothing to pull yours off and give it a go. Who knows?

Scoots

If i do change to an OMVL R90E do i have to change the all the LPG electrics as well???

I don't think so as the LPG regulator is vaccuum driven so anything should work. You can get brand new OMVL for cheap from UK on Ebay. Some tickford systems use them too.