Technical SEICENTO 1.1 mpi cold started in 3 cylinders.

[Alfa33boxer81]

Hello everyone,
Today I started my SEICENTO after two days of not using it, and strangely enough it was firing only in thre cylinders for the first 10 sec or so and then after that ran again normal. There was no smoke or anything
In the last few days has been very cold in here, but today the temp was above zero. Liquids and spark plugs are relatively fresh and the engine doesn't consume , oil or coolant...

Any idea on where to star checking? The car is used every day to go to work and drives 60km of highway. It runs trouble free


Thanks in advance

 

[bugsymike]

I would be tempted towards coils/leads and spark plugs.
The coil/HT leads side as after salted roads from the icey weather some of it can get into engine compartment and cause leads to short.
Less so an issue with spark plugs unless they haven't been changed for a while and the gaps get big, this causes the ignition coil to have to make a larger spark to jump the gap and so electricity like water takes the easiest route and shorts out giving a misfire.
Some years ago my sister had a misfire on a Honda she bought new and always had serviced by the same dealer, they sold her very expensive new ignition coils but issue came back so I told her to tell them to fit new spark plugs, they didn't want to as they were not due according to their service plan, I told her to insist and the misfire was cured.
I am an old school mechanic.

 

[Alfa33boxer81]

I would be tempted towards coils/leads and spark plugs.
The coil/HT leads side as after salted roads from the icey weather some of it can get into engine compartment and cause leads to short.
Less so an issue with spark plugs unless they haven't been changed for a while and the gaps get big, this causes the ignition coil to have to make a larger spark to jump the gap and so electricity like water takes the easiest route and shorts out giving a misfire.
Some years ago my sister had a misfire on a Honda she bought new and always had serviced by the same dealer, they sold her very expensive new ignition coils but issue came back so I told her to tell them to fit new spark plugs, they didn't want to as they were not due according to their service plan, I told her to insist and the misfire was cured.
I am an old school mechanic.

Thanks for the very quick answer bugsymike.
I'm also old school, but just a hobby screwer and I like to take some care of my own cars, well if and when is possible.

First some short info:

Spark plugs, coils and HT leads have been replaced at some point last year or beginning of this year (can't remember when I changed them) but in any case they have not done more than 10.000 km. It also makes sense what you saying about coils/leads in relation with the salt and also the spark plugs gap theory is very plausible as I drive 90% only in the autobahn, and to tell the truth I have a pretty heavy foot for such a little car. I normally drive between 130-max speed most of the time, as the highway from my town to my work has no speed limit. Also owning an Alfa Romeo Giulietta QV 1.8 tbi 235 hp, and using it as an weekend fun doesn't help the little Fiat, which get a little abused through the rev range. This might well lead to a quicker spark plugs deterioration (bigger gaps) in shorter time.
As for the topic, cold you please tell me exact code for the right NGK plugs for the 1.1 mpi engine. I'm not 100% sure if the once I installed last time are the correct plugs or not. I found some NGK codes here in the forum and just bought them, but if someone can give the right NGK codes I would really appreciate it. I can pull them out and inspect them, and then fit a new set just for the peace of mind.


Best
Elvis

 

[bugsymike]

Thanks for the very quick answer bugsymike.
I'm also old school, but just a hobby screwer and I like to take some care of my own cars, well if and when is possible.

First some short info:

Spark plugs, coils and HT leads have been replaced at some point last year or beginning of this year (can't remember when I changed them) but in any case they have not done more than 10.000 km. It also makes sense what you saying about coils/leads in relation with the salt and also the spark plugs gap theory is very plausible as I drive 90% only in the autobahn, and to tell the truth I have a pretty heavy foot for such a little car. I normally drive between 130-max speed most of the time, as the highway from my town to my work has no speed limit. Also owning an Alfa Romeo Giulietta QV 1.8 tbi 235 hp, and using it as an weekend fun doesn't help the little Fiat, which get a little abused through the rev range. This might well lead to a quicker spark plugs deterioration (bigger gaps) in shorter time.
As for the topic, cold you please tell me exact code for the right NGK plugs for the 1.1 mpi engine. I'm not 100% sure if the once I installed last time are the correct plugs or not. I found some NGK codes here in the forum and just bought them, but if someone can give the right NGK codes I would really appreciate it. I can pull them out and inspect them, and then fit a new set just for the peace of mind.


Best
Elvis

With my regular customers during servicing I used to fit new spark plugs at 6000 miles as my customers put reliability above cost, many who I had worked on their vehicles for over 25 years, I always used NGK spark plugs after working as Foreman at a Mazda Dealership in the 70s and found them totally reliable. The other thing I did was fit non resistor plugs as I consider modern cars over "resisted" with resistor plugs, leads, coils, rotor arms etc. and had noticed when using a diagnostic tuner that each one added to the kilo volts required to fire them.
I found this in old books, apologies for the poor photo quality. What it basically says is RC9YC Champion Spark Plugs .6mm plug gap and NGK BKR6ES, the R being the resistor. Do check elsewhere to confirm as old books and even older operator.

 

[shera2025]

Hello everyone,
Today I started my SEICENTO after two days of not using it, and strangely enough it was firing only in thre cylinders for the first 10 sec or so and then after that ran again normal. There was no smoke or anything
In the last few days has been very cold in here, but today the temp was above zero. Liquids and spark plugs are relatively fresh and the engine doesn't consume , oil or coolant...

Any idea on where to star checking? The car is used every day to go to work and drives 60km of highway. It runs trouble free


Thanks in advance

Sounds like a brief cold-start hiccup, which isn’t uncommon, especially in low temperatures. I’d start by checking the ignition side plugs, leads, and coil pack as well as looking for any moisture around them. If it clears after a few seconds and doesn’t repeat, it’s usually nothing serious, but worth keeping an eye on

 

[Alfa33boxer81]

With my regular customers during servicing I used to fit new spark plugs at 6000 miles as my customers put reliability above cost, many who I had worked on their vehicles for over 25 years, I always used NGK spark plugs after working as Foreman at a Mazda Dealership in the 70s and found them totally reliable. The other thing I did was fit non resistor plugs as I consider modern cars over "resisted" with resistor plugs, leads, coils, rotor arms etc. and had noticed when using a diagnostic tuner that each one added to the kilo volts required to fire them.
I found this in old books, apologies for the poor photo quality. What it basically says is RC9YC Champion Spark Plugs .6mm plug gap and NGK BKR6ES, the R being the resistor. Do check elsewhere to confirm as old books and even older operator.

Thanks bagsymike for the information above. Well my Giulietta used the upper range of the NGK plugs which have officially long intervals of 60k km (but I always change them at 30k/40k km), so i guess the fire engine is not of an exclusion where the spark needs changing also earlier taking in consideration the typology of the simpler spark plugs used.

I'll probably go and order a new set of plugs as for what they cost better safe than sorry.


I think the NGK code you gave me is the right one but I'll double check. I prefer NGK even though lately the quality seems not as good as before. Not a big fan of Champion though but heard from my mechanic (an old freak of Italian engineering) that Champion is doing quite well lately.


Will be ordering 4 NGK plugs and change them in garage, even the car has been great after the cold start yesterday with no troubles

 

[Alfa33boxer81]

Hi shera,

As I specified the coil pack and silicone leads are relatively new, I have changed them around 10k km ago, but I don't exclude the possibility of some moisture from the outside on them. The only thing not changed after buying this car last year is the battery which seams a little weak lately with the cold environment.


I don't know how plausible is that a possible valve lash out of spec might cause such a thing, but this is one thing I still need to check as I already have 134k km on the tacho and to tell the truth once the engine is warm the idle has always been a bit rough

 

[Mike1alike]

Considering all the details you gave, I'd say it could be an air problem.
First thing, having in mind the problem is on cold and I presume also high atmospheric humidity, the intake manifold gaskets could be worn out, the ones between gasket and CH. They allow small vacuum leak that ECU can deal with. ECU maintains correct intake manifold pressure by opening less the throttle or the idle air control valve (I don't know which of the to you have, if you have fly-by wire or cable operated throttle body). So, overnight there is condensation on the Cylinder Head and water gets inside combustion chambers, that's why the problem.

If not that (like you also put recently new intake manifold gaskets - and by the way, test the vacuum leak easy, this way: engine running, cover with your palm the TB opening. If no leaks, engine should cut off immediately. If engine is still running, just RPM drops, means there is vacuum leak. Try locating by sound where that is, it does make an increased noise on the vacuum leak point), there could be problem with the intake, again don't know which throttle body you have. But either one, either the IACV, either the TB but are dirty and sticky and that doesn't allow enough air to get in.
My personal say is it's the first one I've said, the gaskets. Because when you start the engine there is no vacuum yet, the pressure inside manifold is the same as atmospheric pressure, it takes a few engine revolutions to build vacuum.

 

[bugsymike]

Re the spark plugs, like you I prefer NGK to Champion, even though I used to race Karts with R49 Champion plugs from distant memory in late 60s in two stoke Villiers engines running Castrol R vegetable Racing oil.
Another thing I have noted with modern fuels is they leave a deposit on the porcelain insulator around the electrodes.
Do you still have E5 or only the higher Ethanol E10 petrol?
The plugs will probably do more miles but with the higher voltage coils these days I found the plug electrodes wore away more creating a bigger gap and so needing higher voltage again to fire them.
I am not a fan of cleaning plugs even though back then we had a Champion Spark plug cleaning machine with sand blaster as it was possible to test a brand new plug to the point it broke down , sand blaster and test it again and it would break down earlier.

 

[Alfa33boxer81]

Considering all the details you gave, I'd say it could be an air problem.
First thing, having in mind the problem is on cold and I presume also high atmospheric humidity, the intake manifold gaskets could be worn out, the ones between gasket and CH. They allow small vacuum leak that ECU can deal with. ECU maintains correct intake manifold pressure by opening less the throttle or the idle air control valve (I don't know which of the to you have, if you have fly-by wire or cable operated throttle body). So, overnight there is condensation on the Cylinder Head and water gets inside combustion chambers, that's why the problem.

If not that (like you also put recently new intake manifold gaskets - and by the way, test the vacuum leak easy, this way: engine running, cover with your palm the TB opening. If no leaks, engine should cut off immediately. If engine is still running, just RPM drops, means there is vacuum leak. Try locating by sound where that is, it does make an increased noise on the vacuum leak point), there could be problem with the intake, again don't know which throttle body you have. But either one, either the IACV, either the TB but are dirty and sticky and that doesn't allow enough air to get in.
My personal say is it's the first one I've said, the gaskets. Because when you start the engine there is no vacuum yet, the pressure inside manifold is the same as atmospheric pressure, it takes a few engine revolutions to build vacuum.

Hi Mike and thank for the reply,

I have no fly-by wire THB but just a normal mechanical one operated by a cable. It is not new but fully functional and already cleaned so is the stepper motor for the idle. Last time I checked it was 2 months ago when I did change the cylinder head cover gasket...it was clean like the first day I cleaned it. I remember at some point this year I also have done this same test of blocking the THB opening with my palm, and if I remember correctly the engine shat down immediately. I was doing some test at the time as I was suspecting some false air was coming in from somewhere as the idle with a warm engine is a bit rough, but at the end I wasn't able to determine this and I'm pretty sure there is no false air or vacuum leaks at all. At the end I gave up and just decided to live with it...i mean with the slightly rough idle (I have read that this is somehow normal on the 1.1 mpi engine). Maybe worth redoing this test after all this time.

It was very humid that morning when the problem occurred, but if the car is used every day there's no problem at all. Something else to add is that if you like to start the car when the engine is already hot, it take a few cranks more to get it running, but nothing exaggerated. When cold it starts within half engine revolution.

 

[Alfa33boxer81]

Re the spark plugs, like you I prefer NGK to Champion, even though I used to race Karts with R49 Champion plugs from distant memory in late 60s in two stoke Villiers engines running Castrol R vegetable Racing oil.
Another thing I have noted with modern fuels is they leave a deposit on the porcelain insulator around the electrodes.
Do you still have E5 or only the higher Ethanol E10 petrol?
The plugs will probably do more miles but with the higher voltage coils these days I found the plug electrodes wore away more creating a bigger gap and so needing higher voltage again to fire them.
I am not a fan of cleaning plugs even though back then we had a Champion Spark plug cleaning machine with sand blaster as it was possible to test a brand new plug to the point it broke down , sand blaster and test it again and it would break down earlier.

I use no E10 and I never mean to use it, I use just normal E5 95 oct from the very well known Aral here in Germany, the same brand of petrol but in the 102 octane version I use for my Giulietta QV and I never had any problems. Aral is normally one of the few operators which offer top Tier fuels and the base product comes from BP and than developed further by Aral.


Cleaning the plugs it's out of question, I'll just get a new set and good is that. Probably as you say the gap has got bigger and maybe the electrode has worn out with the km. Worth giving a try anyway, for what they cost

Another thing, I don't know how sensitive this engines are regarding the air filter, but now that I think about it hasn't been changed since I bought the car 15 months ago, even though it still looks clean

 

[Alfa33boxer81]

Re the spark plugs, like you I prefer NGK to Champion, even though I used to race Karts with R49 Champion plugs from distant memory in late 60s in two stoke Villiers engines running Castrol R vegetable Racing oil.
Another thing I have noted with modern fuels is they leave a deposit on the porcelain insulator around the electrodes.
Do you still have E5 or only the higher Ethanol E10 petrol?
The plugs will probably do more miles but with the higher voltage coils these days I found the plug electrodes wore away more creating a bigger gap and so needing higher voltage again to fire them.
I am not a fan of cleaning plugs even though back then we had a Champion Spark plug cleaning machine with sand blaster as it was possible to test a brand new plug to the point it broke down , sand blaster and test it again and it would break down earlier.

I use no E10 and I never mean to use it, I use just normal E5 95 oct from the very well known Aral here in Germany, the same brand of petrol but in the 102 octane version I use for my Giulietta QV and I never had any problems. Aral is normally one of the few operators which offer top Tier fuels and the base product comes from BP and then developed further by Aral.


Cleaning the plugs it's out of question, I'll just get a new set and good is that. Probably as you say the gap has got bigger and maybe the electrode has worn out with the km. Worth giving a try anyway, for what they cost

Another thing, I don't know how sensitive this engines are regarding the air filter, but now that I think about it hasn't been changed since I bought the car 15 months ago, even though it still looks clean

 

[bugsymike]

If air filter seriously blocked I would have thought car would just generally be flat/gutless.
I recall many years ago on an original/classic mini someone holding the accelerator pedal down to the floor and it struggling to reach 1500rpm, then as the wing nut on the air filter was slackened the engine revs just shot up, so fairly conclusive.
Another thought re misfire looking on the dark side, you mention changing the head gasket a few months ago, a classic sign of head gasket seepage is a misfire on starting from cold, which soon clears on revving engine, as water is cleared from spark plug
This also may show as a strange colouring of antifreeze on that spark plug compared to the others.
Where only a small leak not losing much water a engine "leak test" often shoes it using compressed air down the plug holes using an adaptor on air line hose, I use 150psi, but 90psi is generally enough, with engine locked at TDC on combustion stroke on each individual cylinder and with the coolant cap off but filled to the brim, then after a short while the coolant starts to overflow showing which cylinder is leaking.

 

[Alfa33boxer81]

If air filter seriously blocked I would have thought car would just generally be flat/gutless.
I recall many years ago on an original/classic mini someone holding the accelerator pedal down to the floor and it struggling to reach 1500rpm, then as the wing nut on the air filter was slackened the engine revs just shot up, so fairly conclusive.
Another thought re misfire looking on the dark side, you mention changing the head gasket a few months ago, a classic sign of head gasket seepage is a misfire on starting from cold, which soon clears on revving engine, as water is cleared from spark plug
This also may show as a strange colouring of antifreeze on that spark plug compared to the others.
Where only a small leak not losing much water a engine "leak test" often shoes it using compressed air down the plug holes using an adaptor on air line hose, I use 150psi, but 90psi is generally enough, with engine locked at TDC on combustion stroke on each individual cylinder and with the coolant cap off but filled to the brim, then after a short while the coolant starts to overflow showing which cylinder is leaking.

I didn't change the cylinder head gasket, but I changed the valve cover gasket (the rubber one on top) because I had some nasty oil swiping from valve cover. Sorry for the wrong explanation.


Regarding the cylinder head gasket, that was my first thought as I have experienced the same thing before many years ago on my Alfa Romeo 33, it was the same exact thing but after a couple of weeks/months one morning it hydro locked itself up and wouldn't crank until I took the spark plugs out.
In this case with my SEICENTO is that I haven't even added a drop of coolant in about a year, it doesn't need and the coolant level it's alway stable. I presume that if coolant (even a tiny amount) is somehow making its way in the combustion chamber through the head gasket I would expect the coolant level to drop slightly and needing top up every now and then.


Regarding the air filter, I would say it's not that dirty and the engine revs freely so no issues but I'll put a new one anyway.

 

[bugsymike]

I didn't change the cylinder head gasket, but I changed the valve cover gasket (the rubber one on top) because I had some nasty oil swiping from valve cover. Sorry for the wrong explanation.


Regarding the cylinder head gasket, that was my first thought as I have experienced the same thing before many years ago on my Alfa Romeo 33, it was the same exact thing but after a couple of weeks/months one morning it hydro locked itself up and wouldn't crank until I took the spark plugs out.
In this case with my SEICENTO is that I haven't even added a drop of coolant in about a year, it doesn't need and the coolant level it's alway stable. I presume that if coolant (even a tiny amount) is somehow making its way in the combustion chamber through the head gasket I would expect the coolant level to drop slightly and needing top up every now and then.


Regarding the air filter, I would say it's not that dirty and the engine revs freely so no issues but I'll put a new one anyway.

Oh, that good then!
So if misfire only recent after bad weather maybe ignition coil/leads area.
Not something if you have a weak heart, but I used to run my hands around the coil and lead area to detect any shorting around there.
As an apprentice in the days of exposed plug terminals we had an 80 year old uncle of the bosses, who could stop an engine by putting his hands across all four plug terminals.
Mind you he was a tough old guy, as a mechanic on seaplanes before WW1 he used to have to stand on the floats and start them by pulling on the propeller then jumping back into the sea out of the way, so if he hadn't tuned the engine right and it didn't start he then had to climb out soaking wet and try again.

 

[Alfa33boxer81]

Oh, that good then!
So if misfire only recent after bad weather maybe ignition coil/leads area.
Not something if you have a weak heart, but I used to run my hands around the coil and lead area to detect any shorting around there.
As an apprentice in the days of exposed plug terminals we had an 80 year old uncle of the bosses, who could stop an engine by putting his hands across all four plug terminals.
Mind you he was a tough old guy, as a mechanic on seaplanes before WW1 he used to have to stand on the floats and start them by pulling on the propeller then jumping back into the sea out of the way, so if he hadn't tuned the engine right and it didn't start he then had to climb out soaking wet and try again.

I can handle this thing with the hand on the coil and leads...it will remind me of the times when I was still a teenager and running on 2 stroke bikes and Vespas, where not using any lead caps for the plugs and putting the wire just a few mm away from the plug for not fouling it. I miss this electric shock from the past ahahah

 

[bugsymike]

I can handle this thing with the hand on the coil and leads...it will remind me of the times when I was still a teenager and running on 2 stroke bikes and Vespas, where not using any lead caps for the plugs and putting the wire just a few mm away from the plug for not fouling it. I miss this electric shock from the past ahahah

Lots of fun as teenager with cheap old scooters and motorbikes, wish I still had them now, they would be worth a fortune.