Hello!

My Punto 2000 1,2 8v gives only Fault code for " Cyl 1 misfire".
Coils, ECU and spark plugs has changed.
Belt has changed 6000km ago.

Signal lamp flash after 40km/h. Running same way without accelerting.

Any Ideas?
Belt jumped? Injectors?

8v isn't coil-on-plug is it? Did you change the plug leads as well?

Yes I did.
And have changed different coils and plugs and leads.

So, let's follow this back from plug tip to ECU:

Spark plugs (replaced)
Plug leads (replaced)
Coils (replaced)
ECU to coil pack part of the wiring loom (not replaced)
ECU (replaced)

Electrically then, I would be looking at the wiring loom and its connectors. A bit of electrical contact spray can work wonders at the connectors. However, am I right in saying that the 8v is a wasted-spark system? If so, I would expect two cylinders to have a problem, so that wouldn't indicate electrical to me.

How's your oil and water levels? Any mayonnaise-like substance in the radiator? Any white smoke out of the exhaust?

No Mayonaise or white leak. Levels ok.
It is mystery to me that only one cylinder has this problem. If it´s logical it suppose to be both 1 and 4 cyl, because of the same coil.
I try to go through all connector but don´t find any problems.
Spray suppose to try.
Has injector own code?

I'm just trying to wrack my brains as to how the 1.2 8v detects a misfire. Did you hook it up to diagnostics to determine that cylinder 1 is misfiring? If so, what reader are you using?

I had the same symptoms when my HG went - so do a compression test?

Also could it be a bad injector? so maybe some injector cleaner / fuel system cleaner is worth a try

Connectors cleaned and Camsaft position sensor changed.

What is HG?
Situation still the same.
Misfireing with or without accelerating.

Im using Memoscan. Misfireing is real, because spark looks bad after testing.
It gives code P0301 also without signal lamp signal.

HG=Head gasket ?

Check for spark on #1 .

If spark and plug dry, suspect injector. Try swapping the injectors over, see if misfire follows.

If no spark, suspect lead.

Otherwise, dry and wet compression test.

It is wasted spark, but internal coil faults have been known to cause one cylinder to misfire.

Now more investications done.
1# spark is oily and view in 1# cylinder thru sparkhole is oily too.

Maybe HG quess was pretty much right.

One more test, compression.

tuuba69 said:

Now more investications done.
1# spark is oily and view in 1# cylinder thru sparkhole is oily too.

Maybe HG quess was pretty much right.

One more test, compression.

Click to expand...

Oil in a cylinder might not be a HG tho
Oily filled cylinders is possibly a blown set of rings or bores
There could be a leaky valve seal/stem leaking oil straight on in
There could be cracked Head, Piston etc etc

A compression test will give results on whats going on

Ziggy

Reason was found.

One of Valves has got broken. Piece of valve was missing and compression pressure gone to the valve head.

Littele repairing and Punto will be like new one

Thanks for help!

i would have suggested a vacuum leak off test,this would have shown your problem within 15 seconds of connecting it up