Ford Falcon Engine Problems

From your description it appears it only happens when the brakes are applied so I'd be looking for a vacuum leak associated with the brakes, such as a split or cracked hose or fitting on the brake booster or manifold.

It's likely that there's a problem with the Automatic Fill Limiter in your tank. Have an LPG installer check the car to determine if that is the case and replace it if necessary.

The last E-Gas Falcon ute I tested gave 18.5 L/100 km and I made the comment then that I felt it was too high when a regular petrol six would deliver around 12.5 L/100 km in the same sort of driving. That suggests the E-Gas engine isn’t very economical, and I reckon that’s your main problem. It would depend heavily on the weight you’re carrying and any trailers you might be towing. You could check the normal things, plugs, leads, etc., and you could run higher tyre pressures, but I reckon it’s just the nature of the beast.

It appears to be related to the crank angle sensor, but maybe not the sensor itself. Have you checked the connection to the crank angle sensor?

The AU 2 was mostly a cosmetic makeover of the AU to make it a little more attractive, there were some changes to equipment levels etc., but there were no significant changes to the mainstream six-cylinder and V8. The AU 2 saw the introduction of the dedicated LPG six and a new 200 kW 5.0-litre V8 for the XR8. There’s not reason you couldn’t swap the engines.

Ford will tell you that because it wants to sell you into a dedicated E-Gas Falcon, which has hardened valve seats, valves and even special con rods to handle LPG, but there are thousands of Falcons running around with non-factory dual-fuel systems fitted. In short it can be done and done very successfully. But I would be very suspicious of anyone approaching me with an offer to convert my car, and I would suggest you check their bona fides very carefully. I would also suggest you seek out the expert opinion of recognized specialists in the field to get advice you can rely on.

Ford recommended 91 RON fuel for the XR8 so E10 would be fine with its higher octane rating.

You don't say which type of system you are running, but I will assume it's an old vapour/mixer system as modern injection systems all start on petrol and only switch over the LPG once the engine is warmed up enough to run on it. If your mechanic doesn't know what it wrong with it get him to call the manufacturer of the system and enlist their help, or take it to an LPG system specialist.

THERE were reports of contaminated LPG in some areas a few months ago and you might have fallen victim to this. Make sure any waxy build-up in the system is cleaned out and use a different supplier and different brand of LPG -- if you can.

I ASSUME it's a three-valve V8, and if so it is a common problem. I know one case where the heads had to be removed from the engine so the bits of plug jammed in the threads could be removed safely. It took two weeks and cost a small fortune. It's a problem when the plugs are left unchecked for so long; if they were more regularly removed and cleaned etc, it probably wouldn't happen. I agree it shouldn't happen, and you shouldn't be responsible if the plugs do break. You can fight Ford in the event they do, or maybe you could just leave the plugs alone.