Punto (Mk2/2b) ecu/coil RANDOM fault: is my Punto taking the ****?

[paolonline]

Dear Forumites,
over the last few weeks my Punto (mk2, 2002, 1.2 petrol) has been driving me nuts.
Occasionally, for no apparent reason, it starts going on 2 cylinders, in which case the yellow "faulty injection" warning on the dashboard lits up, and the engine looses power dramatically.
It happened a lot during Christmas time, when starting the engine, and I wasn't overly worried, 'cos I thought it was due to the battery being low as I wasn't driving to work, and 'cos it started working again once the engine was running.
Then it started doing it even while driving, on occasions. Especially when driving in town, with all the stopping, breaking, and starting.
In most cases after a while the car started working fine again. Just like when the engine is flooded (it doesn't work, it doesn't work, it doesn't work, and then all of a sudden it just revs up with a vrooooooommm!!!, and works fine from then on).
I've taken it to my local garage, but it was working fine when they had it, so they had nothing to fix. I took it to another garage out of town, and they changed the coil (coils, actually: both of them).
But the car started behaving the same way shortly after.
Took it again to my local mechanic, and again it worked fine when the car was there.
Last Monday night (21st Jan) I had to call the RAC, cos the car started on 2 cylinders and didn't revert back to 4, so it was undrivable: I thought the coil or ECU had had it for good. The RAC man ran the diagnostic software, which identified a coil/ECU fault. Then he fiddled with the cables connected to the coil, and still the car wasn't getting any better.
After a wee while, when we had both given up hope, the car started again on 4 cylinders with the usual vrroooommmm, to the relief of the RAC mechanic, who had no idea what was going on, or why the car started working again.
He suggested I should get a coil connection checked. Since then, I've had that very connection checked and secured, but the car, on occasions, starts running on 2 cylinders again, with no warning and for no apparent reason.
:bang:
I'd be much happier if it just didn't work, so in trying to resuscitate it the problem would be identified.
But the way it's going just now, the car is a liability, and when I take it to any mechanic it just works fine while it's there.
What to do?

Talked to Fiat in Paisley, they want to run their own diagnostic software (any different from the RAC's? I doubt it!), at a cost of £85 for the pleasure, and take it from there.
Should I take it to Fiat, or try some AutoElectrician first?
Or has anyone had the same on/off kind of problem already, and found a solution that may apply to my devil-car too?
Thanks for reading my post.

 

[fingers99]

See the Guides/FAQs for ECU tests, etc.

It would be helpful to know which cylinders it was misfiring on.

Has anyone changed/checked the HT leads?

 

[RaulCarnahan]

The first things to do is clean throttle body, then change spark plugs, then HT leads and then coilpacks (but you have had this done already)

HOWEVER.... This sounds exactly the same thing that my Punto had. And that was the ECU.
You can either get a new one or have yours fixed. New one will cost you a lot though.
In the end I bought a reconditioned ECU off ebay (you need to get the code right on it though. IAW59F.M2 etc)

 

[Ziggy122]

The connectors dont ever fail on the punto tbh....

Since coils have been replaced - change the HT leads and Spark plugs

As a leaky HT or spark plug can cause odd running symptoms

But it is well worth while doing a ECU check as stated above

Ziggy

 

[paolonline]

Ok, thanks guys!
Well, it appears there could be a number of reasons causing this fault.
But there seems to be more and more evidence pointing at an ECU failure:
. it's not simply the coil (already changed, and problem persisted);
. Punto's ECUs are known to be prone to failing;
. Raul had the same problem and it was the ECU;
. found out there was a leakage of water from the under-windscreen basin right onto the ECU due to a missing grommet (!), which may have indeed the ECU (electronic components don't seem to like water);
So, I think I'll have to swallow the pill and get this ECU reconditioned.
Got a quote from a place in Kent, Remar Re-engineering, for £145 + VAT.
Can anyone beat that (or does anyone have a lead for someone who would beat that?)?
Cheers

 

[fingers99]

Try these . Dunno if they'll be cheaper, though.

Leads are a lot less money -- generally the OE ones don't give reliable results for more than 4 years.

 

[paolonline]

Cheers guys, it was indeed the ECU.
Thanks a lot to Raul Carnahan.
I had the ECU reconditioned from ECUtesting.com, for £130, and now the car works fine.
190,000 mls and counting...