G'day,

Ive done a fair bit of reading on the issue and find allot of issues like my but nothing the same. there are three main issues: 1. rough idle at times, 2. horrible fuel usage (400 k's a tank and that's driving like a granny) it says 12.5 l per 100 on the trip but ide reckon its getting 15 / 16 if its lucky. 3. occasionally when accelerating it seems to loose all power and then suddenly regain. normally when going up a hill and under load (today the car had 5 people and i had it half way to the floor but it did virtually nothing for 5 seconds) it doesn't jolt back into life, more like if you were smoothly accelerating.

i replaced coil packs, plugs and fuel filter 6 months ago (7000k's) and pulled the rocker off last weekend to fix a oil leak and in the process cleaned the throttle body and took the cam solenoids out and cleaned them thoroughly. they were as clean as anything to begin with anyway. ide say its fuel
(leaning towards pump? ) it has done 313,000k's. It also seems to lack a bit of power under WOT from what ide expect having driven an fg and ba v8, although they are both different kettles of fish. i should probably add the auto is a bit rough and might just be slipping, although the revs dont go up durring this. i dont want to just go buying fuel pumps, regulators and sensors for the sake of it, ide rather work out what it is 100% as its my every day car and needs to be reliable

thanks,
Jay

buy or borrow a cheapie bluetooth OBD2 adaptor and plug it into the port in your fuse box.

Then download Torque for Android (borrow an Android phone if you silly enough to buy a teeny tiny iphone as bluetooth adaptors wont' work with iphones because apple seems to think everyonewho wants to make something "talk" to an iphone via bluetooth, should pay them to do so.) You can get around that by getting a 802.11ab/g/n wireless obd2 adaptor.. but it's gonna cost you much more than the 7 dollar cheapies you can get on ebay for Android devices.

Anyway.. once you've got the adapter and borrowed or own and android phone or tablet, download torque.. fire it up.. get the bluetooth adaptor pairing (usually 1111 when it asks) and in Torque you need to choose "Fault codes" and follow the prompts.. it will talk to the PCM and pull up any error codes it finds. If it doesn't know what they mean, google the code with Ford in it...
IE: Ford B1743

And you'll find the answer.. hopefully you will find a dodgy sensor or something.. it's worth doing because it's really really cheap and may well help you get an answer.

If you need a faster answer than that, ring local mechanics, someone will be able to look up the error codes... and it will almost invariably be cheaper than ford dealers.

Thanks for that advice,

I lashed out and bought a scan tool for $20 off ebay, should be here in a few days.

Will it tell me if the thing is loosing fuel pressure intermittently? I wouldn't imagine that there is a fuel pressure sensor? Will it throw up an o2 sensor fault if the thing isnt reading right?

Does anyone know if the trip computer fuel usage is calculated off injector pulse, maf readings or o2 sensor readings. I dont understand why the actual fuel usage is so far out from the trip computer. It would have to be 3l per 100 more optimistic at least. If the 02 sensor were trimming the mixture too rich then i would think that it would adjust the trip reading. maybe the fuel usage and intermittant power loss is totally unrelated.

Thanks,

Jay

The falcons don't have a fuel pressure sensor no... but if the pump is dropping pressure the air fuel ratio would be all over the place and that will throw an error.

Don't know about the trip meter, but it's nothing you can't figure out manually if you don't trust it. Torque has a whole section for tracking fuel use so that may be useful to you also. (and it can display MAF and intake air temp and a bunch of other stuff... only things I've not seen in there are oil pressure or temp and fuel pressure....

you can even add a manual PID to get the BTR auto's temp.

Ok so I bought this off ebay (http://www.ebay.com.au/itm/190848767924 ... 1439.l2649) and it seem to work fine. I downloaded one of the free torque apps from the android store.

No fault codes come up (of course life is never easy) but i did start by taking a drive and some quick readings. at idle with the car in park idling at around 900 rpm after driving i got a coolant temp of 101 c, engine load of 15%, intake pressure of 29.0kpa and an o2 sensor on bank 1, sensor 1 reading of around 0.8 v steady but floating as low as 0.1 volt.

the interesting this is it had a pretty irregular idle. the manifold pressure would occasionally jump to over 34 kpa and it would flatten out a bit but it would almost immediately drop back to around 29 kpa.
I wonder if maybe the map sensor isnt reading right, causing the computer to adjust the fuel ratio wrong?

anyway any advice on what to test for would be greatly appreciated. maybe someone could have a quick look what their timing and intake pressure sit at when in park idling.i know every car is going to be different but if either are wildly different then there is something to start from.i couldn't find an overall fuel trim or mixture value. another thing is the intake air temp was reading about 70c when ambient was less then 20 so maybe this is an issue? i will try and find my vacuum gauge and compare the intake vacuum readings for a start.

Thanks,
Jay

You are getting a pressure reading on the intake manifold?

You should have a vacuum reading on the intake unless it is Turbo and on boost of course. Even at idle Turbos are at vacuum at idle.

Even if the reading is -29kpa, then that is only about 4.25psi of vacuume or around 8.5 to 9 inches of mercury. If this is the case, you have a massive vacuum leak or stuffed valves.

If you vacuum is stuffed then that would explain bad fuel economy and poor resonse.