Technical 1.2 8v misfiring

[varesecrazy]

Hopefully it shouldn't be too costly to sort out!

The only issue is that the engine has moved out of place whilst it has been sat on the jack, hopefully i can move it back into position when i refit the head.

To make sure the job is done properly, how clean does the block need to be to ensure it seals properly?

Do the new head bolts need oiling when i put them in?

Would it be worthwhile purchasing a torque wrench that does angles as well? as i don't have one at the moment

Many thanks, Adam.

hi Adam,

sounds like you are getting on fine,

I use a knife blade to carefully remove any stubborn bits of old gasket,
regularly washing off the 2 x mating faces with petrol..do the Cylinder face 1st as it's a more resilient surface- (for practice..!!)

then do the more easily marked alloy head next, again nice + steady..no rush..,

no gasket goo required on the head gasket they are pre-coated with a tacky spray..so don't wipe them either.. just get all the other parts clean and dry, then get the orientation right, sitting over the dowels..and bolt-up + torque down..!!

I tend to mop out the bottoms of the holes with cotton-buds, then blow out with an airline ( pump),
bolts are suposed to be pre=oiled then left to drip dry..so only mildly oily,

re-torquing down,
I tend to;

use a "norbar" click-stop,

generally its a LOW figure of around 20/30 , then 90' + 90', etc, all in a specified pattern, this info normally comes with the gasket ,

my "secret" is to do all this to the letter of the gaskets instructions..
THEN use a "deflection" type torque wrench( old fashioned = where a pointer runs on top of the "handle" , and as the torque is applied the upper pointer deflects to show torque on a dial/scale next to handle)

in the same pattern as the instructions, gently use the deflection bar to torque up the bolts again.., noting the figure where it "creeps"..(I find usually @ 70.., ) but you can try for lower ..!! initially..,
then nudge every bolt in sequence, seeing what a large variety there is..

MOST will be snug at that figure, however some will creep a fair way.. I am always amazed by how much more they need to reach the same tourque as the rest..

once you've gone around 1 time,
set them ALL to the highest figure 1 bolt creeped at..then you'll know it's actually held down properly

 

[AAB1992]

hi Adam,

sounds like you are getting on fine,

I tend to mop out the bottoms of the holes with cotton-buds, then blow out with an airline ( pump),
bolts are suposed to be pre=oiled then left to drip dry..so only mildly oily,

re-torquing down,
I tend to;

use a "norbar" click-stop,

generally its a LOW figure of around 20/30 , then 90' + 90', etc, all in a specified pattern, this info normally comes with the gasket ,

my "secret" is to do all this to the letter of the gaskets instructions..
THEN use a "deflection" type torque wrench( old fashioned = where a pointer runs on top of the "handle" , and as the torque is applied the upper pointer deflects to show torque on a dial/scale next to handle)

in the same pattern as the instructions, gently use the deflection bar to torque up the bolts again.., noting the figure where it "creeps"..(I find usually @ 70.., ) but you can try for lower ..!! initially..,
then nudge every bolt in sequence, seeing what a large variety there is..

MOST will be snug at that figure, however some will creep a fair way.. I am always amazed by how much more they need to reach the same tourque as the rest..

once you've gone around 1 time,
set them ALL to the highest figure 1 bolt creeped at..then you'll know it's actually held down properly

Thanks for the advice!, all i have is standard torque wrench at the moment, would this be sufficient for the job?

Also do you have any tips of cleaning the engine block?

Clemo Fiat said I should just reuse the old head bolts, is this a wise decision??

 

[varesecrazy]

I added to the cleaning part..,
head bolts CAN be re-used once,
my panda is the only set I've ever bought,
as I knew for sure they'd already been torqued twice..,
your call--personally I would re-use genuine FIAT rather than risk a junk set bought today..!!

torque wrench will be fine..,
I'm sure that's what most garages use.. just be VERY careful with your 90' turns..as that's where all the torque discrepancies creep in .

 

[AAB1992]

hi Adam,

sounds like you are getting on fine,

I use a knife blade to carefully remove any stubborn bits of old gasket,
regularly washing off the 2 x mating faces with petrol..do the Cylinder face 1st as it's a more resilient surface- (for practice..!!)

then do the more easily marked alloy head next, again nice + steady..no rush..,

Almost finish the cleaning, has taken well over 4hrs! I've cleaned the block up as best i can trying to remove virtually all traces of the old gasket. All that's left is use air to clean out the bolt holes, and go over everything with some petrol. There are some minor imperfections on the block surface but hopefully it should still seal properly.

Still haven't heard from the machine shop about the head, hopefully they will ring tomorrow.

 

[varesecrazy]

Almost finish the cleaning, has taken well over 4hrs! I've cleaned the block up as best i can trying to remove virtually all traces of the old gasket. All that's left is use air to clean out the bolt holes, and go over everything with some petrol. There are some minor imperfections on the block surface but hopefully it should still seal properly.

Still haven't heard from the machine shop about the head, hopefully they will ring tomorrow.

looking good..!!

minor imperfections are just that.. it's scratches you want to be wary of.. but I suspect you've just got little pockets / pits which are just the nature of the block,

I hope you get it back in time to build it over the weekend,
Charlie

 

[AAB1992]

looking good..!!

minor imperfections are just that.. it's scratches you want to be wary of.. but I suspect you've just got little pockets / pits which are just the nature of the block,

I hope you get it back in time to build it over the weekend,
Charlie

Hello again! The engine is finally back together! The cylinder head needed quite extensive repair (valves seats, stem seals, all clearances very out, skimming, 1 exhaust valve, decoking) hence why it’s taken 2 weeks re-fit. I decided to fit original fiat parts for the head gasket repair to be sure of the quality.

It took quite a while to get the timing right, although I’m still not sure its 100% correct. The markings on the camshaft sprocket are quite difficult to see. The timing was slightly out when I disassembled the head. When I looked on the coil pack side, I tried to get the camshaft aligned horizontally (offset bellow the centre line) as that's what the Haynes manual says for the Punto (only book to hand). The only reason why I mention it is the car seems slightly down on power. I did set up the crank correct afterwards. I haven’t had chance to give it a good service yet, but I did notice the water pump showed signs of leakage. I intend to get new timing belt + tensioner, water pump, new spark plugs, oil + filter change, coolant flush + fresh coolant and recheck the timing.

At least it starts now and doesn't run on 3 cylinders

 

[The Black Box]

Glad its on route to getting sorted one tip I learnt of this forum is to tighten head bolts to the torque then put a little dob of paint at the top of each bolt you can then easily see what angle it's too and where in sequence you are at

 

[varesecrazy]

Hello again! The engine is finally back together! The cylinder head needed quite extensive repair (valves seats, stem seals, all clearances very out, skimming, 1 exhaust valve, decoking) hence why it’s taken 2 weeks re-fit. I decided to fit original fiat parts for the head gasket repair to be sure of the quality.

It took quite a while to get the timing right, although I’m still not sure its 100% correct.
At least it starts now and doesn't run on 3 cylinders

iIfound similar ,
couldn't decide between 2 teeth.. ,
once I fitted a new belt kit ..things aligned perfectly,


the 8V engine is pretty forgiving, I would use it quite happily a tooth or 2 out,
until you get the Cam-belt + waterpump done,

(I never disturbed the cam-timing.. so can't comment there),

Charlie

 

[AAB1992]

iIfound similar ,
couldn't decide between 2 teeth.. ,
once I fitted a new belt kit ..things aligned perfectly,


the 8V engine is pretty forgiving, I would use it quite happily a tooth or 2 out,
until you get the Cam-belt + waterpump done,

(I never disturbed the cam-timing.. so can't comment there),

Charlie

I've been driving it for a few days now (less than 50 miles) and I've noticed fuel consumption is very poor especially when accelerating. The car probably has 75% of its previous power; it’s sluggish below 2000 rpm, hesitant under acceleration and idles poorly.

I've plugged the car into multiscan and checked various parameters which all seem normal (also no fault codes). I re-did a compression test and all cylinders have 12.5 bar. It all seems to be indicative of a mechanic issue.

I'm going to change the water pump today, if I find the timing to be out is there any other way of checking its accuracy other than by lining the timing marks up by sight? The camshaft timing marks are not very clear to see, should i use a mirror or something like that?

Many thanks, Adam.

 

[varesecrazy]

Hi Adam,

sounds like it's 1 tooth out.. is it hesitant at low revs,
then comes in around 2000 rpm witha surge..?? - that's what mine did,

I tried to take some pics for a guide when I changed my belt a month ago.. unfortunately my son has needed to borrow the car since.. so I've got no further..!!,

the are some half-decent threads lately in the Punto Mk2 section..for the 1.2 8 Valve.. belt timing.

Charlie

 

[AAB1992]

Hi Adam,

sounds like it's 1 tooth out.. is it hesitant at low revs,
then comes in around 2000 rpm witha surge..?? - that's what mine did,

Charlie

Yes, it’s jumpy below 2000 rpm then after that it’s not too bad, there is a delay in acceleration below 2000 rpm. The new timing belt (Fiat original part) has yellow timing marks on it, so I suppose if the engine is timed up right the yellow lines should match with the cam and crank marks!

I'll give it ago, I’ve come this far already! I want my panda back on the road!

Thanks for all the invaluable advice, it’s much appreciated!

 

[varesecrazy]

YES.. the timing marks on belt should be spot-on, better than with an old - stretched belt..,

I take it you didn't move the pulley on the Camshaft..!! ??

have fun..!!

 

[varesecrazy]

Almost finish the cleaning, has taken well over 4hrs! I've cleaned the block up as best i can trying to remove virtually all traces of the old gasket. All that's left is use air to clean out the bolt holes, and go over everything with some petrol. There are some minor imperfections on the block surface but hopefully it should still seal properly.

Still haven't heard from the machine shop about the head, hopefully they will ring tomorrow.

POST # 24 = am I looking at this pic funny.., ( I'm on pain killers..!!)

3 pistons at TDC and one DOWN..??

Charlie

 

[AAB1992]

POST # 24 = am I looking at this pic funny.., ( I'm on pain killers..!!)

3 pistons at TDC and one DOWN..??

Charlie

Haha it does look like that from that angle!

As for the timing, you were correct, it was 2 teeth out!

 

[varesecrazy]

Haha it does look like that from that angle!

As for the timing, you were correct, it was 2 teeth out!

great.. on BOTH counts..!!

do I take it it's now running beautifully..



just ordered a few service bits for mine..,as it's got an annoying minor hesitation / misfire,

plugs + leads.. think the leads are factory originals..so done well



Charlie

 

[AAB1992]

great.. on BOTH counts..!!

do I take it it's now running beautifully..

Charlie

Well all I've done so far is take the old belt off, get the timing right and fit the new water pump. I'm going to leave the silicone to set overnight and then put the new timing belt on.

Fingers crossed it will run much better

The car is like a friend to me, I've had 5 years and 75k of almost faultless service. I miss getting into it everyday. Haha I think I've become too attached

Hopefully (touch wood) it will continue to be reliable

 

[varesecrazy]

any better..??,
Charlie

 

[AAB1992]

any better..??,
Charlie

Sorry for the late reply!

Yes the car runs much better!

Shame about the water pump. The loctite silicone i used was rubbish! I left it to set for 24hrs and water poured out of it as i was carrying out a coolant flush the next day!! I haven't got round to using a different silicone.

Are there any good alternatives, that would work better?

Adam

 

[varesecrazy]

Hi Adam,

I feel your pain.., :hug:
got sold the wrong sealant for a sump pan.. HELLUVA MESS!!..3times..:bang:

my panda's pumps were always done at a fiat/alfa indy,

pretty sure it's an RTV silicone they use..as I phoned them after the sump fiasco..

it comes in a (GUN mounted ) TUBE like UPVC - mastic sealant


hopefully somebody will confirm the correct spec, @MEP - or the other one jon1612

will probably know :worship:

cheers,
Charlie

 

[The Black Box]

I use the high temp stuff from toolstation it's red can't link as it'll give the whole page code is 66124 £5.26 for a 310ml tube you put in a cartridge gun. Always worked for me on sumps and water pumps and it's cheap compared to other stuff goes to 300 degrees