Hello, I have a Fiat Punto 1.2 8V 1998 year.Car occasionally runs on 2 cylinders.Changed - engine sparks,cable plugs and coils.but problems remain.As warm very much operate normally.


p.s Sorry for my English but I have not studied.I use the translator of google

Epetuk said:

Hello, I have a Fiat Punto 1.2 8V 1998 year.Car occasionally runs on 2 cylinders.Changed - engine sparks,cable plugs and coils.but problems remain.As warm very much operate normally.


p.s Sorry for my English but I have not studied.I use the translator of google

Click to expand...

Hi, and welcome,
check it is definitely losing spark power on these occasions,

not jut a mechanical fault disabling 2 x cylinders

Charlie

Don't know if it would cause misfire but crank position sensor?

maybe I did not make myself properly. Spark power there are 1 and 4. control signal nozzles 1 and 4 stopped



p.s Sorry for my English but I have not studied.I use the translator of google

so you changed spark plugs, ht leads and coil packs but car still runs randomly on 2 cylinders
car starts to run on 2 cylinders when it warms up or it also does it sometimes when its cold? are there any lights on dash?

Whatever the problem turns out to be, do not drive more than a few yards on just 2 cylinders. It will go quite well but do not be tempted. You will burn out the catalytic converter with the petrol that is now pouring through the exhaust pipe without being burned first !!

This is not guesswork, it happened to me a few years ago when a pair of coils went open-circuit and I drove home from work about 20 miles.

When I replaced the coils and the catalytic converter I also replaced the crank position pickup and made sure it was close to the toothed wheel. They can get eroded by muck flung off by the wheel teeth.

No random cylinders - are only just 1 and 4.Changed - engine sparks,cable plugs and coils.the problem disappears when heated coolant level include cooling fan

It's clear to me that a pair of coils has failed in some way or has some intermittent breakdown. The coils feed cylinders 1&4 and 2&3 respectively. You need to test the primary and secondary windings on all 4 coils with a resistance meter, getting the same results for all 4 coils primary windings and then secondary windings, although the resistance of primary and secondary cannot be expected to be the same. Open circuit [hence no sparks] is shown by very high resistance in 100,000's of ohms. However an intermittent fault may easily pass such a test and the easiest way out is to go to a scrapyard looking for a car that was driven there, and get the complete coil and mounting assembly with the plug leads and plug boots, clean them all up and swap them for your own.

There is the slight possibility that the ECU box is faulty and they do go wrong sometimes without breaking down completely, but I doubt it in your case.

Lastly you could make sure the plug wires are neatly routed and not crossed with themselves or other wiring or cables, to eliminate the possibility of crossfire, although with only 4 cylinders this isn't probable.

I hope all your spark plug gaps are correct?

Autoservice came to the conclusion that the problem is as follows - there is a problem in the management of the coil which feeds 1 and 4. This stops management for the nozzles 1 and 4. The options are: a weak link somewhere along the line itself or ECU, that controlled this .Interesnoto coil is that the impact of an ECU to solve the problem.


p.s Sorry for my English but I have not studied.I use the translator of google

Epetuk said:

Autoservice came to the conclusion that the problem is as follows - there is a problem in the management of the coil which feeds 1 and 4. This stops management for the nozzles 1 and 4. The options are: a weak link somewhere along the line itself or ECU, that controlled this .Interesnoto coil is that the impact of an ECU to solve the problem.


p.s Sorry for my English but I have not studied.I use the translator of google

Click to expand...

ok- to recap;

when engine is COLD - it runs on cylinders 1 and 4 ( 2 +3 have ZERO SPARK)

when engine is HOT - it run on ALL 4 (1,2,3,4 = good)

is this correct..??


if so there have been issues of the actual spark / coil trigger terminals of the ECU failing ( bad soldering)

Charlie

Upon ignition can be on all cylinders maybe 2 and 3 .If the movement of the car from time to time handle on all cylinders again and returned to the 2 and 3 (1 and 4 stop) .When heated to include cooling this problem is gone.


p.s Sorry for my English but I have not studied.I use the translator of google