Help With AUII Fairmont

SteveFGF6 · 03-12-2011, 11:24 AM

Hi all, i'm hoping someone here can help me. I have an AUII Fairmont with 265KMs on it. Around town it runs beautifully, auto shifts smoothly, crisp acceleration etc. Problem starts when going on a cruise, after approx 75 k's on the highway, the auto keeps swapping from 4th-3rd every couple of k's. Went for a 300k drive yesterday, car was doing the same, but also "chugging" and running roughly for the first 200k's, the last 100 k's it ran great, no sign of problem. When i came home, first 100k's all good, middle 100k's running rough & auto going up & down between 4-3 more frequently than ever before, last 100k's car seemed to run more "rough" than before. Auto was serviced & flushed 5K's ago, i know it's near the serviceable end of it's life, but my gut feel is that there is an electrical/fuel/spark/ecu issue that's making the Auto behave in this way, & also run poorly. I plan on changing plugs, cleaning throttle body & resetting ecu, do you think this will cure it? Any input greatly appreciated
Thanks,
Steve

Day-mow · 03-12-2011, 12:02 PM

hmmm coil pack been replaced? or o2 sensor?

SteveFGF6 · 03-12-2011, 12:10 PM

Neither of those done, if i took it to Ford, would these show up as faults when scanned? Would that make the auto behave in this way?

Steve

mik · 03-12-2011, 03:18 PM

dunno mate, lots of things can alter car behavior, sometimes it`s a combination of things, you just have to check everything easy ones first and eliminate them one by one, but you`ve got a few k`s up so by my reckoning it might be some part/s at the end of their service life, fuel pump perhaps, ignition parts, this is assuming it`s all well else where, electrical system ok? battery terminals/leads, earths, no auto oil leaks? , no vacuum leaks, never had my car scanned, i suspect it would speed up the diagnosis though.

SteveFGF6 · 04-12-2011, 11:15 AM

Thanks mik, as you say, start with the basics & see what happens. I cleaned the T/B this morning, holy ***** it was filthy, enough gunk to cover a whole square of absorbent towel!! That will account for the poor running, but will that explain the behaviour of the auto? I don't know enough about sensors & computers in cars to figure out if a T/B is that dirty, will a sensor of some description give a false reading to the ecu, which causes the changes to the auto. I hope the last sentence doesn't make you all think that i'm "fertilizing the rub tree"

rowan194 · 04-12-2011, 02:42 PM

Hmm, if the AU had dual throttle position sensors I'd suggest the trans one might be borked, so it thinks you're suddenly putting the foot down a bit more, but I think there's only a single TPS now?

I seem to recall something about an overheating transmission switching to limp home mode (locked in third) until it cools down. How long does it stay in third? Does your ECON dash indicator blink when it happens?

XRGhia · 04-12-2011, 02:54 PM

FYI, my old AU Wagon use to skip between 3rd and 4th at 75km/h.... 70km/h is the shift point for 3rd-4th, so if you go up a slight incline/use a bit of acceleration, it'll go back to 3rd until you come off the accelerator...

SteveFGF6 · 04-12-2011, 05:15 PM

Thanks for the input guys. The tranny shifts from 4-3 on flat ground with no change in speed, or throttle input. It will hold 4th momentarily, then go back to 3rd for maybe 2oo metres, then back up to 4th momentarily & so on. Cleaning the T/B didn't fix the rough running either, it is a little better, not much. Rowan, i think there's only 1 TPS from what i can see in the workshop manual. I thought it might be the inhibitor switch on the side of the 'box, but a scan will show if that is faulty. I have heard that only Ford dealers have all of the necessary diagnostic tools to perform scans, can anyone confirm.

Cheers,
Steve

rowan194 · 05-12-2011, 08:52 AM

Does ECON flash? Maybe whatever decides the trans is overheating (a temp sensor or thermostat?) is faulty.

Do you experience any shuddering when cruising then applying more accel, and once you back off the engine surges? That's an overheating trans.

All fluid levels normal?

How long since the leads (not just plugs) were changed?

Mr Hardware · 05-12-2011, 10:35 AM

Quote:

Originally Posted by xrghiawagon

FYI, my old AU Wagon use to skip between 3rd and 4th at 75km/h.... 70km/h is the shift point for 3rd-4th, so if you go up a slight incline/use a bit of acceleration, it'll go back to 3rd until you come off the accelerator...

Nope
Shift point on the flat under no or extremely little accel from 3rd to 4th is 56kmh. If you're going 75kmh or thereabouts, it's likely you're actually experiencing torque converter lockup in top at this speed - from memory mine does it just a tidbit over 80.

Dropping back to 3rd at 75kmh is going to produce about to 2400rpm - are you sure she's going to 3rd? Have you manually shifted to 3rd to see if it is actually 3rd?
Many a man has been fooled by the torque converter lockup in the BTRs mistaking it for a gearchange.

SteveFGF6 · 05-12-2011, 09:58 PM

Econ doesn't flash. Trans has new oil & filter, and new trans cooler fitted the day before i took the trip i described at the beginning. I reset the cpu this morning & it ran great-really crisp with no spluttering etc. Every now & then i "feel" a little miss upon acceleration at lower speeds. My mate has a scanner & it showed low voltage across the TPS, i will install a new one in a couple of days, maybe that's been the problem all along, can i be that lucky??
Fluid levels are normal, haven't changed plugs or leads, but will do in next week. When it drops back to 3rd @ 100 km/h, revs go to around 3000. Normally is on 2000 in 4th @ 100km/h. I have shifted to 3rd when it drops down & it is actually 3rd-that was the first thing i did when it started playing up as i also thought about torque converter lockup. Oh well, the saga continues. I can see it crapping itself the night before we drive to Sydney.

mongrelEF · 06-12-2011, 12:56 AM

From memory, the AU drops into limp mode on engine overheat - and also drops a couple of cylinders on a rotating miss.
Perhaps the coolant sender in the back of the head is playing up? They have been known to crack and cause weird issues.

Mr Hardware · 06-12-2011, 10:44 AM

Oh wow, it actually drops back to 3rd (3000rpm) at 100kmh?

She's broked man. New trans time. Or at least a significant overhaul.

XRGhia · 06-12-2011, 10:46 AM

^^^ Or the trans is just overheating?

4ford · 06-12-2011, 01:47 PM

or maybe the transmission has got water in it, via the internal radiator heat exchanger leaking and allowing water to get into the transmission oil system.

just a thought, it's happened!

SteveFGF6 · 06-12-2011, 08:55 PM

Yeah, i'm thinkin new tranny, it has done a few k's i guess!! I thought if it went into limp home mode it locked in 3rd, but as it goes back & forth between 3-4 i discounted it. It has been running great ever since i did the throttle body & reset the cpu, but as i have said in a prior post, something just doesn't feel right, i have no confidence in the car if that makes sense. Luckily those BTR autos aren't too rare. Thanks for the input everyone, will keep updating.
Steve

rowan194 · 06-12-2011, 09:29 PM

AFAIK:

Limp home would need a reset by restarting the engine. My EA2 Falcon used to get stuck in limp home occasionally.

Trans overheat switches to 3rd until the overheat condition is gone, so it doesn't require a restart.

howfor54 · 14-01-2012, 01:03 PM

Is your battey past best? A friend with 6 speed BF had a similar problem, the dealer couldn't find it, but someone else fixed the problem with a new battery. Elcetronics don't like low voltage.

5.0 ED · 14-01-2012, 01:22 PM

This also happens from a faulty gear position sender, or a faulty TPS signal, being the TPS run's both engine and trans doesn't make much difference, trans still goes into 3rd for limp, engines can however still run fine without a TPS, most of the time the only thing you will notice is when you pump the accelerator, it'll bog down from having a non correct TPS signal to tell it to pump additional fuel in.

EA's function very differently under fault compared to later models like AU. If an AU EEC senses a fault and then the fault fixes itself, it will start using the sensor again, where as EA wont.

Another possibility is that your gear position level is not correctly adjusted or has a broken engine/trans mount, making the shift level move a little bit into 3rd, when up top its in 4th. If it is you would tell by moving the gear selector.

And if its the gear position switch playing up, if you sit in the car and grab the gear shift and just continuesly move it from park to 1st with engine not running, and just keep doing it for a bit, it should come good for a while, basically they get dirt on the tracks and moving the selector back and fourth wipes it each time.