For the last couple of weeks my Myltipla petrol 00 has been misfiring. Generaly this has occurred when under load eg high gear and heavy throttle. Single misfires has also occurred when letting the throttle up initialising a enginge break.
The issues have been more frequent when the engine have been cold. The issues have occurred more frequently over time and now the idle is also very rough raising and falling as if one cylinder is cotting out.
The engine oil is nice and clear brown and not conntaminated with water. I have changed spark plugs and checked the ignition cables and they seem to be ok.

Is there any usual suspects for this type of fault on a petrol multipla?
Is there a way to get fault code readouts on this enigine?

Could be loads of things...cam and crank sensors are my bet or it could be maf sensor or even fuel pump?
Buy a cheap vag cable of ebay and install a free version of fiat ecu scan
Follow instructions (i suggest you print them) and plug your multipla to read error codes stored in your ecu

Hook it up as mentioned fir fault code.
However I'd be leaning towards the coil pack myself.
Marty.

Martyc's probably right. You've described the classic symptoms of a defective coil pack.

No simple way of checking though, simply replace and see. And a dealer isn't likely to take it back if that's not the problem. About a hundred quid...

Thanks for all good advice!

I have now manage to get hold of a ODB cable and have checked the fault codes. Stored Codes are:

P0105 Map/BAro Preassure - Signal Low - Light ON
P1325 Knock Sensor - No Signal
P0351 Ignition Coil - Signal Low - Light ON

I have not seen the engine light come on since i bought the car a year back so I am therefor a bit pussled by those codes. I removed the codes and went for a 15min drive. The car still runs poorly but no new codes were generated. I guess I will start by trying to figure out if the knock sensor is working properly.

Does anyone have any info on how to locate and check the knock sensor?

Knock sensor is unlikely to be causing your problems as you hsvd described them as getting progressively worse and erratic.
If the sensor went to fault it would retard your timing equalling crap performance but consistently crap performance.
If the knock sensor was being activated by knock you'd have different codes.

I'd be looking on eBay for an ignition coil...
A test for the ignition coil can be done using an am radio... Google it but it won't always work.
Marty.

I have now taken a longer drive and the problems seems to be consistent. Under load at low rpm I have constant misfires. As soon as i rev up end get above 3000 rpm it smoothens out and becomes less obvious. I dont think I am experiencing any great loss of power on higher revs, but it is a bit hard to tell.
No new fault codes during this second test drive either. I will drop by my parts store and pick up a new coil pack asap.

I have now replaced the coil pack but without any result. I have driven quite a bit today, but have still no new fault codes.
I noticed that the hose from the cranc case vent is cracked. To me it seems unlikely, but maybe this puts the mass reader off.

Sorry Erik, wish I hadn't suggested the coil pack now, when it didn't do the trick...

That's the unfortunate thing, sometimes it's replace and try - keeping your fingers crossed! You did have them crossed?

Yikes... Your sure it's a misfire and not something else??..fuel starvation would be next based on your symptoms.
Might be worth a try running the engine withe hood open in the dark... One of the ignition leads may be arcing to ground, and if your lucky you may see this.. Watch your hands in the dark tho.
Hope you can return the coil pack or at least eBay it.
Marty.

Did u try running it with the maf unplugged??

God jul to you all!

I have run the engine in the dark, but can not see any stray sparks.

It could indeed be fuel related, but it seems to me as a fuel preassure / starvation problem be obvious on higher revs as well. But maybe a clogged injektor could result in this behaviour. I will check the plugs again and try to spot wether a cyl is running lean.

I think it was a good thing to change the coil pack anyeay, It was badly cracked and I got a cheap replacement.

I did not know that you could run without the Mass sensor. Is this just a matter of unplugging tha MAF? How will the ECU react on this?

Yes just unplug it, it will be just after your airbox... The ecu will acknowledge it's no longer connected and adopt a base value for air mass.
You'll see a logged error code next time you hook up your obd .. Just clear it but there's no panic all will be working as it wad once you plug it back in again.
Worth a try, it's not recommended to run like this longterm... But that's debatable depending how much actual control the sensor value can swing the fuel mixture.
Have a nice Xmas.
Marty.

I have checked the plugs again and they are all a bit on the bright side suggesting that the engine is running a bit lean. The color of all four plugs are however very consistent.
I have been trying to locate the Mass (MAF) sensor but without any result. On the back of the intake manifold i located the MAP sensor wich i test unplugged resulting in a fault code and a bit (not much) caughing. On the back of the throttle body i found two sensors wich seems to be throttle position and idle controll.

Searching the forum on MAF sensors only lead to results regarding the JTD version.

After a bit of research It appears as if the petrol (1,6 16v) model does not have a MAF sensor, so that is ruled out then.

As I was looking through the service history i found that two of the injectors was replaced about five years ago. I measured the resistance of the injektors and it was all very stable around 16,5 Ohm. After this I ran the injektor relay check in FiatEcuScan, but was unable to hear the injectors klicking. Some fuel must have been pumped through anyway. When I turned over the engine I blew the intake manifold... So, I guess i will be replacing this before moving forward with the troubleshooting

On a positive note the car ran remarkably well with a taped together intake manifold! Some irratic reving on idle, but nothing to crazy. Now I am celebrating that I managed to get back without a tow.

Don't know if they'll ship to Sweden for you, but it's got to be worth a try at this price:

http://www.ebay.co.uk/itm/FIAT-MULT...arts_Vehicles_CarParts_SM&hash=item3a6ed6ccca

Lots of other Multipla bits there as well. I've got no connection with them whatsoever, so come crying to me if their stuff is a crock of poo.

Thanks for the tip. I have found a manifold at the local scrap yard at a good price. I have fitted the new manifold, and when doing so i found that the fuel line was heavily deformed. The fuel line is a plastic pipe that runs inside a rubber hose. This must have been squeezed under the manifold due to inproper placement during a previous montage. I thought that this might be the problem and replaced the fuel line with a regular fuel hose.

But not.... The engine still runs really bad. Now the idle is now pulsing in a 4 second phase between 800rpm and 3000rpm. Cold this be a leak in the manifold? Or is it time to try to replace the throttle house?

With the manifold i also got a complete fuel rail and a set of injectors. I was thinking that i might give it a try and change the injectors, but i find it unlikely that a faulty injektor should affekt the idle. Could it?

Worth mentioning is that i still have no new fault codes albeit the very obvious fault

I am starting to run out of ideas...

Today i replaced the fuel rail with all four injectors and the vacum hoses from the cranccase breather. This sorted out the strange pulsating idle, that was probably caused by a vacum leak.

The engine still runs poorly om low revs and heavy load. And the idle is still a bit rough.

I still have no fault codes apart from that the airbag light came on after replacing theinjectors

I finally have the Multi running properly. The problem was a vacum leak in the throttle housing. The leak ws to small to be detected with start gas, but i heard a hissing noise when reving the engine and managed to locate it.

Now I need to adress the airbag issue that occured when searching for the engine fault. I guess i might have damaged some sensor or cable in the process.