Technical 2004 Panda 8V hunting on idle??

[NornIronItalian]

Hi

Sorry my 1st post is asking questions, but.....

My Dad's Panda has started hunting, its only been noticed since the weekend. I fitted new HT leads at the weekend, car started and drove fine. I twas yesterday morning my Dad went out to start it before going to work (the battery is draining for some unknown reason and was flat on Monday morning, another thread up shortly) Only thing that has been done has been the HT leads fitted, I done a full service a couple of weeks ago, replaced plugs, oil & air filter and a few other brakes and suspension bits. Dad said he noticed a small misfire so I decided the HT leads could need replaced as they looked old and had gone hard.

When he came home yesterday, he told me about the hunting, its fine when cold, when it comes off fast idle, it drops to 850rpm then a few seconds later revs between 500 - 900rpm, holding a slight throttle to 1000rpm and its fine.

Points to an air leak to me, however I can'f find any leaks using WD40 or see any pipes split or cracked but I can hear a slight hissing near the air con pump.

My question is, are they any common faults on these wee cars, such as manifolds cracking? Any thing else I could have overlooked? I will probably have to start stripping the car at the weekend to see what I could find, but it would be handy to know a few common faults to point me in a direction. No engine light on and no other symptoms.

Thanks in advance

Andy

 

[lamlash]

That will teach you for servicing it!

I'd first double check the spark plugs you fitted were definitely the right ones - lots of threads on here about the correct type). Did you fit genuine Fiat HT leads? I tried some Bosch ones which didn't fit very well.

It does sound like an inlet manifold air leak -not sure if WD40 will help you detect it - I have only ever tried with carburettor cleaner spray (be careful not to set anything hot on fire though). I haven't heard about common faults on the inlet manifold.

Finally, the ECU on these engines is very sensitive to battery voltage and I wouldn't rule this out as the cause of your hunting problem. If you have an ammeter you could check what current flows when everything is off to see if something is draining the battery. I'd expect a few tens of milliamps only (but have never tested this). Courtesy light staying on in the boot maybe? First sign of a failing battery tends to be clock resetting itself when you start the engine from cold - have you had that yet?

Hope some of this helps. Do let us know how you get on.

 

[NornIronItalian]

Hi, thanks for that

Yeah, kinda sorry I opened the bonnet now, but hey ho!

Plugs where NGK's with a 14mm thread, the car drove for 2 weeks fine with these plugs in, this problem has only started since the weekend. Dad says tonight it does it when sitting in traffic, so I'm confident now its a new fault and not an existing unnoticed fault.

It was Bosch plug leads which I got, from Halfrauds, believing that Bosch was a good name, but as you have said, I'm not very happy with the fit, so I think the 1st thing I will try is the genuine leads from Fiat as I remember during my Mazda years, the Mazda's were very fussy about their leads as well.

The car is suffering a battery drain issue, which I seem to have narrowed down to the radio and hasn't caused problems unless he forgets to switch it off before switching the engine off, said radio is on the list for replacement, but with that in mind, I will check charging voltage ect as well.

WD40 is good for finding manifold leaks, when sprayed over the leak the engine speed will rise slightly, basically anything flammable will do the same job, but WD40 is slightly messy lol

 

[Goudrons]

The way to test for parasitic battery drains is to:
Turn everything off, close doors etc.
Undo the neg terminal from the battery.
Set a multimeter to read amps and bridge the gap between the neg battery post and the disconnected neg lead with the mulitmeter.

Without any drain the draw should be somewhere in the region of 0.03 or 0.04 amps.

If you detect a draw that is much higher, start pulling fuses one at a time to locate which circuit it's on (pull the right fuse and the amps should drop to a level stated above)

Most drains can usually be traced back to duff fitting of aftermarket head units.
These usually need to be fed by two lives.
A constant live which is used to store the setting/stations, this draws very little power.
And a switched live from the ignition which actually powers the unit.

Rig this switched live incorrectly to a constant source and the head unit will draw around 0.4 or 0.5 amp all the time, causing a big enough drain on the battery.

 

[NornIronItalian]

Hi guys, sorry for the lack of input to the forum.

The hunting fault I am putting down to the HT leads, poor fitment Bocsh ones, going from what I've read on this forum, genuine leads are the only way? Anybody tried a different brand with any sucess? £50 for 4 leads seems an awful lot!!

The radio fault seems to have gone, Dad turns the radio off before switching the car off, and we haven't had an issue since.

 

[varesecrazy]

does it run better with a full battery?,

I put cheapie leads on my Punto - damn near identical , and didn't have any issues,
generic set were @ £20,
you may have been unlucky with the Botch set,
Charlie

 

[AAB1992]

Hi

Sorry my 1st post is asking questions, but.....

My Dad's Panda has started hunting, its only been noticed since the weekend. I fitted new HT leads at the weekend, car started and drove fine. I twas yesterday morning my Dad went out to start it before going to work (the battery is draining for some unknown reason and was flat on Monday morning, another thread up shortly) Only thing that has been done has been the HT leads fitted, I done a full service a couple of weeks ago, replaced plugs, oil & air filter and a few other brakes and suspension bits. Dad said he noticed a small misfire so I decided the HT leads could need replaced as they looked old and had gone hard.

When he came home yesterday, he told me about the hunting, its fine when cold, when it comes off fast idle, it drops to 850rpm then a few seconds later revs between 500 - 900rpm, holding a slight throttle to 1000rpm and its fine.

Points to an air leak to me, however I can'f find any leaks using WD40 or see any pipes split or cracked but I can hear a slight hissing near the air con pump.

My question is, are they any common faults on these wee cars, such as manifolds cracking? Any thing else I could have overlooked? I will probably have to start stripping the car at the weekend to see what I could find, but it would be handy to know a few common faults to point me in a direction. No engine light on and no other symptoms.

Thanks in advance

Andy

It happens on my 2004 1.2 8v panda every year! I seem to think its linked to the weather, sudden changes in temperature and all that. Mine does clear up in its own time if i leave it alone. I've been down the same route as you, changing plugs, leads etc. but to no avail. What also works is if you reset the car via the fiatecuscan/mutiscan software, by carrying out a self-adaption reset. You hit execute, then hold the revs at 4500rpm for about 3 seconds, and do this 3 times. The car then takes a good 50-80 miles to calibrate all its parameters again and behold, silky smooth idle!

 

[NornIronItalian]

does it run better with a full battery?,

I put cheapie leads on my Punto - damn near identical , and didn't have any issues,
generic set were @ £20,
you may have been unlucky with the Botch set,
Charlie

Battery would generally always be fully charged, its used everyday. Spoke to my Dad, think he's going to try another set of leads from eBay

 

[varesecrazy]

Battery would generally always be fully charged, its used everyday. Spoke to my Dad, think he's going to try another set of leads from eBay

OK,
used every day / fully charged don't always mean the same thing on modern vehicles,

good luck with your replacement set - let us know how it goes,

Charlie

 

[NornIronItalian]

All is does is a 20 mile trip in the morning and again in the evening, so I'd be confident the battery would be well charged. Thanks for the tips, I'll let you know how the after market leads go