glenn2602 said:

Sorry to butt in guys - I have a Cinquecento. The misfiring/kangaroo petrol/stalling took me a few days to suss out. There were no error codes ..

Disconnect the electrical connector on the MAP and run the car. If the symptoms disappear or seem to have 'eased' .. suspect the MAP.

As a rough rule of thumb, worn piston rings burn oil and leave a cloud of smoke behind when you accelerate. A burnt or split exhaust valve can cause what feels like a misfire. A compression test followed by a 'wet' compression test can help identify the problem

** Before anybody rushes off and pays lots of money to have a new head gasket .. try one of the modern head-fix additives. I'm told that the 'steel seal' is excellent.
http://www.ebay.co.uk/sch/i.html?_odkw=punto+map&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR6.TRC0.A0.H0.Xcylinder+head+fix.TRS0&_nkw=cylinder+head+fix&_sacat=0

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Problem still not fixed. Have not managed to get a compression testing unit yet, new throttle body has not fixed the issues (so new Throttle position sensor and idle air control valve came with.)

Tried a new MAP sensor at the scrapyard and the problem did not improve.

The oil is getting used up fast, but not seeing particularly much of anything coming out of the exhaust.

I wonder if the exhaust valve you mentioned could be it, how easy to change ?

Paul

You have a new throttle position sensor and air idle valve, so they can't be at fault. However, try disconnecting the battery for 20 minutes to see if the air idle valve (also sometimes called a stepper motor) will reset itself.

To change the exhaust valve(s) you have to remove the cylinder head. You would also have to remove all valves and bits and pieces from the head before taking it to an engineering shop to have it skimmed. It isn't a difficult job removing and overhauling a cylinder head - just time consuming and slow.

Having said that, your cylinder head may not actually need skimming. Because of its shape a cylinder head warps - bends upwards in the middle - banana shaped. This is due to heat in the centre and cooler air around the outside.

If the car hasn't overheated, the head may not be warped. You can check it yourself by holding a steel rule lengthways along the head. You can clean and polish a cylinder head by sticking medium grade abrasive paper onto a sheet of glass or wood and rubbing the head across its width .. not along its length. Then give it a polish with fine abrasive paper.

Though of course there's no point in removing the head unless you suspect something is wrong. You say the oil is getting used up fast but you can't see any visible smoke. You're absolutely certain that there are no oil leaks?

If there are no oil leaks the engine is burning oil. The oil will be either trickling down the valve guides into the bores whilst the car is standing - this is usually due to worn valve guides/stem seals. At start up from cold you may get a cloud of blue smoke which quickly disappears.

The alternative is that the piston rings/bores are worn, allowing oil up into the combustion chamber.

Check your spark plugs - are any of them blackened or oiled? An oiled or burnt plug can cause a misfire.

You need to do a compression test to find out the state of your engine. That's a dry compression test followed by a 'wet' test. If you're not sure what to do, let me know.

glenn2602 said:

You have a new throttle position sensor and air idle valve, so they can't be at fault. However, try disconnecting the battery for 20 minutes to see if the air idle valve (also sometimes called a stepper motor) will reset itself.

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I'll try this today but don't hold much hope, it was probably unplugged for 20 minutes anyway when I was replacing the throttle body.

glenn2602 said:

To change the exhaust valve(s) you have to remove the cylinder head. You would also have to remove all valves and bits and pieces from the head before taking it to an engineering shop to have it skimmed. It isn't a difficult job removing and overhauling a cylinder head - just time consuming and slow.

Having said that, your cylinder head may not actually need skimming. Because of its shape a cylinder head warps - bends upwards in the middle - banana shaped. This is due to heat in the centre and cooler air around the outside.

If the car hasn't overheated, the head may not be warped. You can check it yourself by holding a steel rule lengthways along the head. You can clean and polish a cylinder head by sticking medium grade abrasive paper onto a sheet of glass or wood and rubbing the head across its width .. not along its length. Then give it a polish with fine abrasive paper.

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Sounds hellish (for someone like me) if the head is warped, I wouldn't have thought the car had over-heated since I've never seen a warning light. That said my Punto is so cheap there isn't even a temp gauge to see if it's running hot often.

glenn2602 said:

Though of course there's no point in removing the head unless you suspect something is wrong. You say the oil is getting used up fast but you can't see any visible smoke. You're absolutely certain that there are no oil leaks?

If there are no oil leaks the engine is burning oil. The oil will be either trickling down the valve guides into the bores whilst the car is standing - this is usually due to worn valve guides/stem seals. At start up from cold you may get a cloud of blue smoke which quickly disappears.

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I think at least a little bit of oil, is leaking out of the rocker cover gasket round the back, (right where the spark plugs are). It doesn't look particularly significant though.

glenn2602 said:

The alternative is that the piston rings/bores are worn, allowing oil up into the combustion chamber.

Check your spark plugs - are any of them blackened or oiled? An oiled or burnt plug can cause a misfire.

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I'm not sure if it's cyclinder 1 or 4 but the one on the far left, from the point of view of sitting in the car gets a bit of oil on it somehow.

glenn2602 said:

You need to do a compression test to find out the state of your engine. That's a dry compression test followed by a 'wet' test. If you're not sure what to do, let me know.

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Compression test impossible unless I buy a compression thingy. I'm tempted to just try and get rid of the car ASAP

Paul

No1 spark plug will be nearest the timing gear.

The plug is getting oiled up - oil on the electrode?

glenn2602 said:

No1 spark plug will be nearest the timing gear.

The plug is getting oiled up - oil on the electrode?

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Yes there has been oil on the electrode, I would guess then that it's number 4? I'm assuming the timing gear is on the right hand side from the point of view of sitting in the car, where the crank sensor, alternator etc is ?

Paul

Yes, that's probably right .. so you're talking about cylinder No4.

Oil on the electrode suggest bore/ring problem, though having said that, a compression test is the only way of knowing for sure.

It may be worth your while asking a workshop for a second opinion/doing a compression test for you. Once you know what the exact problem is you can then decide what to do about it.

Did you find a solution for the rough idle problem? I have exactly the same problem, tried many things but still couldn`t fix it.

I created another thread about it here:
punto-ii/451883-fiat-punto-mk2-2b-1-2-8v-2004-rough-idle-mostly-electric-load.html

mikeb1 said:

Did you find a solution for the rough idle problem? I have exactly the same problem, tried many things but still couldn`t fix it.

I created another thread about it here:
punto-ii/451883-fiat-punto-mk2-2b-1-2-8v-2004-rough-idle-mostly-electric-load.html

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I Have already responded to Mike's question over on Youtube, but for the benefit of anyone else following this thread or reading in the future...

Unfortunately the car ended up scrapped as it lost compression completely on I think 3&4 (Wrongly said 1&2 on Youtube comment) cylinders.

I / we're not 100% sure whether it was piston rings, head gasket or other as my girlfriend is not car minded but the mechanic was Finnish and I don't speak Finnish too well.

I'd definitely recommend anyone with a similar issue taking to a trustworthy mechanic, I spent quite a bit of money in the end chasing small possible causes (even though I was warned directly and indirectly through reading other posts about this), and in the end the estimated repair bill far exceeded the cars value. Quite a blow to spend a lot of time and a fair bit of money, only to have to then scrap the car anyway...

The only real option other than taking to a mechanic would be if someone is willing to lend a donor car to try the parts, or a good scrapyard that'll agree to let you try parts and only buy if it fixes. This saved me at least from wasting money on a MAP sensor for example which wouldn't have helped.

Paul

Let me add the link to the other thread I created about the ongoing investigation of my similar rough idle problem, since the issue was closed but not solved in this thread.

https://www.fiatforum.com/punto-ii/...ough-idle-mostly-electric-load.html?p=4277748

For future reference, my 2000 1.2 8v had a rough idle when I bought it last year. A year and a half later the head gasket crapped out. Replacing the head gasket also fixed the rough idle.