Technical Cylinder head failure - Punto 1600

[boguing]

That's too fast to be once per two revolutions (so more than one valve). Are you sure you've got the inlet and exhaust valves correctly identified and adjusted?

Might also be worth running it with the belt cover off to make sure nothing's amiss in there.

 

[fingers99]

Check that there's plenty of oil beneath the cam cover -- it is possible, on some FIAT engines, to put the head gasket on the wrong way round, effectively cutting off any oil flow to the valve gear.

 

[chesh]

Valves are ok (0.4 inlet, 0.5 exhaust).
There was plenty of oil when I took the cover off. it covered up the shims and bolts.

 

[fingers99]

Did you measure the clearance at base circle on each cam lobe?

Valve spring out of spec?

Worst case scenario is that the welding distorted the head. While the mating surface will have been rendered flat by the skim, the cam bearings are cast into the head, so may have distorted meaning the cam itself is either trying to bend or running out of true one end.

 

[chesh]

I have another problem.
Drove the car for like 3-4 hours today, everything was ok until I nearly got home, car started to loss power. almost made it home and it started to lag until it shut off.

Couldn't start it anymore.
Checked the HT leads and no. 1 had corrosion on it.

I've replaced that HT lead from my 75 punto. it's not the same but it started ok. still I had loss in power. car won't carry on 1-2 gear and lagging.

Then I cleaned and polished the corrosion and even cleaned plug no. 1. drove for about 20 min then started to lag again and almost shut off.

Do you think it's the spark plug or HT leads even it's cleaned now?
Maybe a faulty coil?

 

[fingers99]

Lagging doesn't really mean much to me. If it was the plug/lead I'd expect a one cylinder misfire.

Is the car overheating? Oil level? Does sound like a car on the verge of seizure.

 

[chesh]

No overheating, oil level is ok.
when I press the gas pedal on 2nd gear, it takes time to move, then all of a sudden gets a power kick.

 

[fingers99]

Is EML on?

That poor car has seen a lot of no love. I'd start with plugs, leads, coil pack, but I suspect a valve or even valve seat issue.

 

[chesh]

Nope Injection light isn't on.
I'll buy new set of plugs and HT leads soon, I hope it's not the coil pack as it's only 1 unit and seem to be very expensive:

http://www.ebay.com/itm/Quinton-Haz...Parts_Accessories&hash=item3a8e58d793&vxp=mtr

 

[fingers99]

I'd not buy a Quinton Hazel one: Chinese Quality Control!

In all this, though, thinking of what would/could cause a lack of power, difficult starting, etc. I'd be inclined to change the fuel filter and do a compression test first.

 

[chesh]

Is there any way to check a faulty coil?

(ok found it on autodata)

 

[fingers99]

That'll work, but can't take into account the effect of temperature.

Notwithstanding which, if there's a spark at 1 and 3, it's very unlikely to be the coil.

 

[boguing]

Can you feel the engine shaking when it 'lags'?

 

[fingers99]

Do all that, then check for fuel past the injector(s) -- wet plugs on cranking and spark. If neither, TDC sensor.

 

[chesh]

TDC=crankshaft sensor? I believe if it was faulty the car wouldn't start right?
anyway drove today for about an hour and the car runs fine.

Checked the crankshaft sensor and it was full with oil on the connector and plug. Cleaned it all:

Don't know if that's a problem, or I'm having problems only when the coil is very hot after long drive.

 

[boguing]

Oil in the wiring is very unhelpful. You may well have nailed the problem.

Coils do get pretty hot - they are doing a fair bit of work.

 

[chesh]

Another thing that bothers me,
Do you know how can I wrap this pipe that goes to the EGR? Is that a fuel pipe?

It seems to get VERY hot.
I've seen 1.6l engines that the pipe has a heat wrap on it:

Should I worry about that?

One more thing which I'm missing is the airbox filter piping:

I see it splits to 2 ways, one that sucks air near the headlight like other puntos and the other thing goes to where?
Can I find that bit on ebay or something or should I make an induction kit and throw away that airbox

 

[chesh]

Today the car is really slow and laggy after a set of fresh plugs and leads.
Checked the fuel pressure and it's around 1-1.5 bar.
Fuel filter is ok. is the fuel pump nearly dead or could it be one of the injectors?

Checked directly from the fuel line, with and without the regulator.

 

[fingers99]

How do you know the fuel filter is OK?

Unsure of what pressure those pumps work at.

 

[chesh]

I've removed the fuel filter and gave a good shot with air compressor gun between the lines + fuel pipes from the engine. no blockage at the pipes.

on autodata it says it should work on 3bar and 2.5 bar with the regulator.
I think it's the same fuel pump like in the 60/75 puntos.