rough idle and running rich

smoo · 19-06-2011, 01:10 PM

I pulled the battery out of my XR6 a couple of weeks ago to jump stat a car. Since then she is running rich (from 750km/tank down to 500) and when pulling up to the lights after slipping it in neutral runs rough with idle fluctuating from 250-1000rpm. It only does this a few times before settling back to 800rpm. I've swapped the o2 sensor for a good one, tried a new battery in it and cleaned the terminals, no difference. MAP sensor looks new and hasn;t thrown up any warning lights on dash (if a faulty one does that?).
I've done a search but haven't found anything under the same circumstances.
The fact it has done this after pulling out the battery has got me buggered.

Any help appreciated as I've resorted to driving a plasticy rattly BA Fairmont Ghia til the AU is sorted.

Mr Hardware · 19-06-2011, 02:55 PM

Hey smoo
Have you done the old clean the IAC trick?
Is it a proper I6 or a VCT alco?
I didn't think I6's had MAP sensors?
How dirty are your air and fuel filters?

Jimmyd · 19-06-2011, 05:21 PM

Did you reset the ECU after reconnecting battery?

smoo · 19-06-2011, 05:47 PM

Quote:

Originally Posted by Mr Hardware

Hey smoo
Have you done the old clean the IAC trick?
Is it a proper I6 or a VCT alco?
I didn't think I6's had MAP sensors?
How dirty are your air and fuel filters?

no mate I haven't had a look at the IAC. And yep she is a VCT.
MAP sensors in these things sit under the throttle body.
Haven't checked the filters, I should probably replace, but considering it played up after removing the battery I'm guessing its electrical, if not a strange coincidence.
Jimmyd yep I did reset the ECU, cheers.

SirHenry · 19-06-2011, 07:01 PM

Hi Smoo,

Mine does this everytime I lose battery power for some reason mine doesn't relearn the base idle. Mine I usually have to take to ford to get the base idle reset and then she's good as gold.

Upon saying that I just a did a battery last month and the battery mob hooked a memory device in the cig lighter and it actually relearned on the run home and for about a week and then good.

But your problem is the base idle being out and needing to be reset it is a pain in the rear. I tried the reset trick and it just still normally does not relearn.

My friend you like me have a Princess Falcon that wants everything.

midgetyone · 20-06-2011, 02:05 PM

Hi,

I had a similar problem with my AU3 XR6 where the ECU had been reset. The issue then very quickly became the idling when coming out of a gear into neutral (or foot on clutch) with rev hunting slowing steadying and a/c would also hunt and slowly steady. It was bad enough it'd actually stall at traffic lights etc.
Did you go through the relearn procedure? If so which one did you follow. I went through mine stumbling a bit cause I couldn't find one for a manual version. My relearn that fixed the problem was as follows;

Find a big flat area (like car park)

-Disconnect battery & reset ECU
-Start car and allow to settle
-Idle 2 min with A/C on in gear with foot on clutch
-Idle 2 min without A/C in gear with foot on clutch
-Idle 2 min with A/C on in neutral
-Idle 2 min without A/C in neutral
-Put car in gear and with no accelerator let out clutch slowly to allow engine to adjust to load change until idling along normally (will probably stall but keep trying maybe a little accelerator to begin with if it can't do it on its own). Once revs steady put clutch in slowly and coast to stop. Do this until car is handling load change without fluctuating. Keep doing this and begin adding things like steering, brakes, a/c, lights etc until all operations smooth.

Took me around 1-2 hours to do. Hope this helps

smoo · 06-07-2011, 08:47 PM

Quote:

Originally Posted by SirHenry

My friend you like me have a Princess Falcon that wants everything.

And here is me thinking it is just another demanding 'coon,

Thanks for the suggestion midgetyone.

I've had it at the auto sparkys, who spent about 8 hrs on it, no fault code logged etc, and all they can find is the o2 sensor is telling the ECU it is running rich, but the ECU isn't doing anything about it. He is stumped and only suggested I replace the ECU but made no guarantees that will slove the problem. As he didn't fix it he only charged me a box of **** so no worries. I think I will take it to a dealer?
I'm getting 13l/100km on flat roads at 100kmh crusie control (!) so I def have a problem lol.
Mr Hardware who are some good wreckers you know of?... the few over here charge an arm and a leg for parts, cheers.

midgetyone · 07-07-2011, 09:01 AM

Leaky injector/s perhaps? Bearing in mind that if you reset the ECU with a problem it learns with a problem and can make problems worse......

SirHenry · 07-07-2011, 06:38 PM

Have they checked the base idle?

Quote:

Originally Posted by smoo

And here is me thinking it is just another demanding 'coon,

Thanks for the suggestion midgetyone.

I've had it at the auto sparkys, who spent about 8 hrs on it, no fault code logged etc, and all they can find is the o2 sensor is telling the ECU it is running rich, but the ECU isn't doing anything about it. He is stumped and only suggested I replace the ECU but made no guarantees that will slove the problem. As he didn't fix it he only charged me a box of **** so no worries. I think I will take it to a dealer?
I'm getting 13l/100km on flat roads at 100kmh crusie control (!) so I def have a problem lol.
Mr Hardware who are some good wreckers you know of?... the few over here charge an arm and a leg for parts, cheers.

FGII-XR6 · 07-07-2011, 08:13 PM

O2 sensor is very likely with high Ks

Mr Hardware · 07-07-2011, 08:14 PM

good wreckers? never heard of em.

XR6AUIINICKS · 10-07-2011, 07:46 PM

very keen to see a fix for this one as my au2 xr6 ute with manual g/b is doin it to have done plugs throttle body clean and fuel filter with no improvments

SirHenry · 10-07-2011, 08:27 PM

Quote:

Originally Posted by XR6AUIINICKS

very keen to see a fix for this one as my au2 xr6 ute with manual g/b is doin it to have done plugs throttle body clean and fuel filter with no improvments

Honestly I'd back the house on it being base idle needing to be independently reset by Ford. I have had the same thing I tried the ECU reset which didn't work on it took it to Denmac Ford 45mins later and $90 they fixed my problem being diagnosed by them correctly as Base Idle needing to be reset.

They only thing this guy has done is removed the battery so in my thinking it shouldn't be anything else other than the ECU losing the base idle setting and not relearning it for some reason.

Yes I know it seems weird but it happens because I have had it happen.

smoo · 10-07-2011, 09:07 PM

Quote:

Originally Posted by XR6AUIINICKS

very keen to see a fix for this one as my au2 xr6 ute with manual g/b is doin it to have done plugs throttle body clean and fuel filter with no improvments

Yep I do about 600km a week so I'm feeling it lol. I've gotta do 2000km next week so it is going to a dealer tomorrow, see what they say hopefully you are right SirHenry otherwise she will suck my bank accounts dry.

I've ruled out all things mechanical as fuel consumption nearly doubled as soon as battery was refitted.

o2 sensor is new btw.

Cheers.

**Stav** · 10-07-2011, 09:33 PM

In my wagon with the big cam I found removing the battery makes the factory ecu tend to run way richer. My advice is disconnect the battery again a few times until it runs somewhat better.I feel the ecu does seem to have a different idle tune each time...I dont know why but it does.

SirHenry · 10-07-2011, 10:01 PM

Quote:

Originally Posted by smoo

Yep I do about 600km a week so I'm feeling it lol. I've gotta do 2000km next week so it is going to a dealer tomorrow, see what they say hopefully you are right SirHenry otherwise she will suck my bank accounts dry.

I've ruled out all things mechanical as fuel consumption nearly doubled as soon as battery was refitted.

o2 sensor is new btw.

Cheers.

See if you can get a quote from the dealerships some can charge a price for a very quick job most of mine at Denmac were 45min jobs on a diagnostic machine (the Ford one). dunno what they did other than that but it fixed it.

Make sure you get a price off em 1st though

SirHenry · 10-07-2011, 10:02 PM

Quote:

Originally Posted by Stav

In my wagon with the big cam I found removing the battery makes the factory ecu tend to run way richer. My advice is disconnect the battery again a few times until it runs somewhat better.I feel the ecu does seem to have a different idle tune each time...I dont know why but it does.

That's a very good idea as well just find an idle you can live with

Mr Hardware · 23-07-2011, 10:52 PM

any progress on this one smoo?

smoo · 24-07-2011, 03:06 PM

No mate hence no reply to the thread. I've been to the dealer, they did bugger all, there are no fault codes logged, they reckon you can't re set the base idle, and I just need to drive it till it 're learns' itself, well *** me I've done 2,000km last week and about 4k since it started happening with no difference.
The worst recorded mileage I got last week was 13.8l/100km, best 12.8 highway 100km/h.
If I could find a wrecked 5 spd VCT I'd buy it and start swapping over parts but are few and far between.
Going off what the auto sparky said, the ECU isn't adjusting fueling for what the o2 sensor is telling it, I will take a gamble and either send my ECU away or buy a 2nd hand one, will try and sort that this week and let ya know cheers.
Never had a efi vehicle do this to me after pulling the battery out.

SirHenry · 24-07-2011, 05:10 PM

Quote:

Originally Posted by smoo

No mate hence no reply to the thread. I've been to the dealer, they did bugger all, there are no fault codes logged, they reckon you can't re set the base idle, and I just need to drive it till it 're learns' itself, well *** me I've done 2,000km last week and about 4k since it started happening with no difference.
The worst recorded mileage I got last week was 13.8l/100km, best 12.8 highway 100km/h.
If I could find a wrecked 5 spd VCT I'd buy it and start swapping over parts but are few and far between.
Going off what the auto sparky said, the ECU isn't adjusting fueling for what the o2 sensor is telling it, I will take a gamble and either send my ECU away or buy a 2nd hand one, will try and sort that this week and let ya know cheers.
Never had a efi vehicle do this to me after pulling the battery out.

I feel for ya Smoo, you would think the dealer would know the cars they sell, the guys that used to be at Denmac in Brisbane knew everything by practical knowledge and fixes and what worked and what didn't.

Only thing I could suggest was what one of the others suggested and try taking the battery out for a while and reset the bloody thing again cause I don't it would get much worse from the sounds of it.

Keep us updated amigo

Chris,

GK · 24-07-2011, 05:23 PM

Quote:

Originally Posted by SirHenry

My friend you like me have a Princess Falcon that wants everything.

Not good, but I guess it could be much worse. You could have a Princess Commodore! LOL!

Hope you guys get it all sorted soon.

GK

mik · 24-07-2011, 05:42 PM

i can`t understand how disconnecting the battery would do anything unless there is a problem elsewhere, i have disconnected mine (vct) many times and not even noticed a difference afterwards, i think i would try a better workshop if the dealer is too useless to work it out.

sd1800 · 25-07-2011, 03:39 PM

I also was experiencing similar problems and chased everything else since my O2 sensor was new. Caused me a major headache. Needless to say it ended up being my o2.

If you have one of the cheap ebay sensors I wouldn't be suprised if that's it..... mine lasted 6 months.

smoo · 31-10-2011, 05:38 PM

I thought I would post an update to this problem, I have had another ECU fitted and a new PCV valve at the same time, fuel consumption is now down to about 11.5l/100km over 2500km since Thursday. Still need to find 3l/100km. Since fitting the new PCV valve the rough idle when coasting in neutral has gone, even though the rough idle happened after I removed the battery

Next plan may be new fuel filter, regulator, fuel rail and recon injectors.
Or just ditch the fckn thing for an XR8.

Dok · 05-07-2012, 07:14 PM

Hi soo, just like to know if ya found out the probs with the falcon ? As a mate has just got one today CHEAP with same thing. We'll go throu the list eg fuel & air filters, reset ecu , New pc valve , New 02 sensor , and if that dont work we'll do as SirHenry said reset base idle. Cheers Dok

Dok · 05-07-2012, 08:35 PM

Hi soo, just like to know if ya found out the probs with the falcon ? As a mate has just got one today CHEAP with same thing. We'll go throu the list eg fuel & air filters, reset ecu , New pc valve , New 02 sensor , and if that dont work we'll do as SirHenry said reset base idle. Cheers Dok

davistev · 02-06-2013, 10:14 AM

Did you ever solve this issue?

4RDXR · 29-03-2016, 07:55 PM

Idle motor is stuffed

**PridenJoy** · 30-03-2016, 03:19 PM

Had this problem with my wagon after disconnecting the battery for a while to install cruise. Ended up doing similar to what Midgetyone suggested and it worked, car is back to normal fuel consumption.

gp351 · 20-05-2016, 10:18 PM

Hi just worked on a XR6 FG problem sort of similar. Only runs rough cold, will almost stall when pulling up to a stop. All OK when its motor has warmed up. Checked air filter OK, cleaned throttle body etc looked quite clean anyway.Checked fuel filter which has only been on for 15000ks, book says they do 90000k (bit of a joke), full of crap!. Fitted new filter and though that should fix it and, seems only slight improvement if any.... thinking maybe crap gone into injectors?. Hope after a few road trips it may settle down?.