falcon au 1 problems

[wahroonga1]

Hi can anybody help me??

I purchased a 1999 AU 1 Falcon Wagon 3 years ago to tow my 1.5 tonne caravan.
Two years ago it developed a very slight miss when travelling in the higher gears ( not towing ), it was hardly noticeable. It also started to miss badly when travelling up hills ( under load ).
Now when towing the van, it will tow reasonably well until I stop for the first pit stop ( usually around 100-150 kms ) then after re-starting it will run like a wooly goat and jerks like mad. It’s duel fuel and when it plays up ( gas and petrol ) it uses a lot of fuel. Normally I get 12 litres per 100 kms on gas but strangely 16 litres on petrol. When it’s playing up I get 30 litres on petrol and 27 on gas.
Have been to several different garages for analysis and they all reckon they have the problem solved ( I wish) Two years on and my bank balance is a lot lighter. It’s done 180,000 km’s.
Here’s what’s been done :-

New fuel and air filter plus PCV valve.
New plugs and Ignition lead set.
Coil pack replaced.
Inlet manifold checked for leaks.
Fuel pressure regulator replaced.
Map sensor replaced.
Fuel pump operation and control relay checked ( throttle body cleaned)

Any idea’s as it’s obviously got the expert’s beat?
It also won't kick down a gear when under load until the pedal is re applied.
Are the two faults connected? Any ideas please..: Davo

[turquoise]

Had a pajero years ago that developed a miss, seemed to happen at random times and get worse the more i drove it. Turn it off for half an hour and it'd go away (for a bit).

Turns out the distributor cap had a very very small crack in it. A drop a water had somehow got in there, it'd vaporise with the heat, the vapour would condense inside the top of the cap, a droplet would form and fall onto a spark, making it miss. I see you already had the coil pack, etc replaced but what about the actual cover?

[Donny]

Could be the TPS or Oxygen Sensor, more likely the O2 sensor is cactus. Was the coil pack replaced with a new one? Was the fuel pump tested not only for pressure, but the correct pumped volume of fuel??

And another big issue of later Falcons was poor earthing, check ALL your earthing points in the engine bay by removing them and cleaning the terminals and the parts where they touch the body. Id also remove any paint behind where the terminal and body connect. Not sure on AU's, but E series had an earth terminal down on the underside of the car near the transmission on the floorpan area, that often got caked with grease n grime etc, and that was a constant earthing issue on those cars..

The kickdown thing you mention could be tied to the TPS not reading correctly..

[wahroonga1]

Thanks for the reply............Davo

[wahroonga1]

Thanks Donny, I'll check those things, specially the O2 sensor and earthing.

[FTe342]

Its either got a problem with both fuel sources or an electrical problem. Being a miss, more likely the latter.

Problem develops after stopping, so heat soak is good possibility. Distributor module or cap is suspect.

Has the car been to Ford dealer for fault code check? Is the car being checked after it gets hot and allowed to sit then re-started?

[XRGhia]

AU's, both I6 and V8 are coil packs....


Old AU1 Futura had a massive miss... Replaced the coil pack, and the fuel filter with brand new genuine items, and it was fine...

..Then it was written off on the 31st March this year, lol...

[wahroonga1]

Yep the coil pack was replaced with brand new, so I guess the next step is the O2 sensor and check earthing points.When does one start thinking about the engine management module ?
Thanks for the replies..........Davo

[b2tf]

Originally Posted by wahroonga1

Yep the coil pack was replaced with brand new, so I guess the next step is the O2 sensor and check earthing points.When does one start thinking about the engine management module ?
Thanks for the replies..........Davo

Hopefully never, shouldnt really require replacing unless it has been obviously damaged. They do sometimes get water in them as the windscreen can leak under the lower cowling but generally you would notice this by water in the footwell area first.

I second the advice to try a new 02 sensor if the ignition side of things has been renewed.

[mik]

if all else fails and the ecu has had wiring tampered with from the lpg installation, i would also check the earth at the ecu behind the left kick panel, also if series 1 is like my series 2 one of the battery leads goes to the bottom of the engine block .....errr drivers side i think, i was doing a service on mine one day just running a spanner over everything and found it only finger tight (another qaulity pre delivery ), good luck with it.