ECON Switch Causing Falcon AU Fault

[publicsp]

Not sure if this is where I should write this information, but it just might save a Ford Falcon owner a lot of money, frustration and time.

Background:
-Purchased a 1999 Ford Falcon AU, 140,000ks, good condition
-All OK, except vehicle would "surge/hesitate" slightly when maintaining steady speed at 50-55k
-Symptoms felt like have a loose chain on your motorbike when cruising at steady slow speed
-Fault would come and go, not consistent, made it harder to find
-Visited various well qualified mechanics, including the local Ford dealer
-Items repaired/replaced in the hunt for the elusive fault:
a) All tyres balanced and aligned, then fitted new rear tyres as they looked a little out of shape
b) Complete new exhaust system
c) New engine seals, dipstick, oil filler cap, all hoses checked
d) New spark plugs
e) New high tension leads
f) Compression checked
g) Fuel injectors cleaned
h) New fuel filter
i) New battery

One day, by chance, I flicked the "ECON" switch to "off" whilst driving with the fault and it disappeared!

Over the next few days I flicked it on/off/on/off when driving (always leaving it off) and the car became more consistently smooth

It is definitely the ECON switch, most days the car is perfect, if not, then a couple of "flicks" later, it is perfect again for the rest of the day.

Not sure how to make the fault disappear altogether, maybe someone else has had this happen.

Thanks.

NOTE: I searched all the Ford Forums during the hunt for this fault, could not find any reference, hence my reason to load this information to help someone else.