jpor

iTrader: (1)

My Mum's car needed a new battery as it's been in the car for over 6 years, and had to be jumped yesterday to get it to start ( Using one of those portable battery jumper packs). The thing is she took it to kwikfit to get a new battery fitted. Now when she comes to a stop the car it stalls . It never did this when the old battery was in.

Could it be that the ECU has reset ?

Any ideas? The battery appears to be connected up properly and I have just had a go at starting it up, given it a couple of blips on the throttle and appears to be okay.

NotoriousREV

Does it also sometimes rev really high for no apparent reason? The throttle position sensor (TPS) is known to be a problem on Ka's and I'd wager that's the problem.

jpor

iTrader: (1)

No. Idle appears to be fine, it's just when you press down on the clutch pedal to come to a stop it happens. It's a bit odd that the battery has just been changed and it's just started to do it. Had a quick google search and someone else has reported the same thing, but had no replies on the subject.
Thanks for replying though.

Allan

iTrader: (1)

Recently been through the same problem, although not after changing the battery. It’s a known issue with the KA.

1. TPS as above.
2. Idle speed control valve.
3. MAF
4. Assorted wiring issues.
5. Anything else that will cause idling issues.

Could be any one of them, although I doubt they would be affected by removing the battery. I'd check around and make sure nothing's been disturbed.

MY money is on the ISCV, about £80 from your dealer and really easy to fit. Don’t be tempted by the cheap ones on ebay. Alternatively if you have a nice dealer you could try and persuade them to swap it over to see if it fixes the problem. Or you could find another KA owner, and ask/bribe/borrow as appropriate.

Also don’t go by the diagnostics information, it’s not always correct.

Allan

Allan

iTrader: (1)

Just read your post above, are you saying that it idles OK apart from when you depress the clutch ?

jpor

iTrader: (1)

Hi Allan. Yes, everything was a okay until the battery was swapped out. Then on the drive back home she noticed when stopping by pressing in the clutch as normal the car stalls.

Thanks.

Allan

iTrader: (1)

Only ask as this comes under my item 4 as above. I did read somewhere that poor idling can be caused by a loom problem which is stressed when you depress the clutch. I've not had this one myself though.

I'm still going with the ISCV.

let us know what it is when you fix it.
Allan

jpor

iTrader: (1)

Thanks for the reply Allan. I can't understand why a sensor could just go faulty as soon as the battery is replaced though . I have noticed on the live wire a small box connected up. What's this for?

Out of a matter of interest, where is the ISCV located? Any piccies you can pot up to show me where it lives? Thanks again.

Allan

iTrader: (1)

Agree that it's unlikely that something has failed, unless it's been damaged by the jump start. I would certainly look for something obvious at first.
The small box you’re referring to is probably a fuse holder, mine has three fuses in it.

Just nipped outside and took a pic for you, neighbours probably thought I was mad

jpor

iTrader: (1)

Thanks Allan

Got more of the story from my mum tonight. Apparrently when she started the car up straight after having the battery replaced at the kwik fit, she says that the car sounded rough like it wasn't idling correctly, and only noticed it started to stall when she came to stop at lights or junctions. The 3 fuses in the fuse box on the live terminal, what do they govern? I'm just wondering if one of the fuses has gone causing the issue?
As far as the jump start, I have done this on more than one occassion, and once jump started the car still ran fine afterwards.

Allan

iTrader: (1)

Don't know what the fuses do, but I guess there something pretty hefty. You should be able to see through the fuse case if there blown.

You could try disconnecting the battery for 10 mins or so which might reset the ECU, could be just that's it's got it's knickers in a twist. Make sure you have your radio code if you do this though.

NotoriousREV

I suspect it's resetting the ECU that's causing this in the first place i.e. sensor has degraded, ECU has "learned" to compensate, reset wipes learning, sensor too far degraded to work properly without correction.

In my earlier post, I blamed the TPS but meant ISCV

Shark Man

This could be a whole host of issues, from a vacuum leak from a pipe thats been disturbed to not bothering to get the engine serviced properly.

As a note, it'll need a run over vary driving conditions to get the ECU to re-adapt as it loses its learnt values when the battery was disconnected, varying speed, vary throttle positions and the engine must get up to full temperature (no 10min runs to the shops and back ). So the car will run rough and be prone to stalling immediately after replacing the battery. This is quite normal. However, after a good run it should be fine, if not you have a problem.

Off the top of my head:

There is a clutch switch that is supposed to raise idle speed when the car is in motion. This act to compeensate for the slow response of the idle control valve, and prevent stalling. The switch/sensor in the gearbox can go faulty or there is a loom problem.

If this is not working properly, then the idle control valve and ECU can be too slow to react to the dropping idle speed. A side symptom sometimes is lack of engine braking i.e no overrun shut off (but its not always the case, and a women driver would never notice it anyway ).

Reading relevent live data from teh ECU with a suitable diagnostic tool will rule this out (not fault codes - they aren't always logged).

Idle control valves either work or they don't, if that was dead it wouldn't idle at all or idle at 1500rpm. Unless it was blocked up, in which a simple flush through with carb cleaner sorts it.


I'd also check the fueling, again, a simple live data check from the diagnostic port combined with checking the exhaust emissions. A ECU reset (battery disconnected) will clear all fueling and ignition adjustment history, If the oxygen sensor (or MAF, or both) are marginal (or slow switching), then this will cause rough running and make the engine very prone to stalling. HC emissions will be poor as will be the AFR, which maybe erratic.

As a footnote....when were the valve clearances last checked and adjusted? (Never do I hear? ), a ECU reset will assume a factory engine, if the clearances are all over the show, its going to run a bit rough afterwards.

jpor

iTrader: (1)

Looks as though Sharkman was right. My mum gave kwik fit a quick ring to tell them the problem, and they said to take the car down for them to have a look at. On the way to the garage it now appears the car is back to normal from the off, without any stalling and what appears to be normal idling . We'll wait and see if it comes back. At least I'm getting some peace and quiet at the moment.

Thanks to all those who replied.

Allan

iTrader: (1)

Good stuff

jpor

iTrader: (1)

Indeed. She went out in it again today and said that it appears to be back to normal. Thank goodness, as she is retired and on a pension, so £70 quid for a new sensor wouldn't have gone down well for her.

Thanks again to all that replied and shared knowledge on the problem.