misfire on my cylinder n°1...

[Supertimor]

Hello, i have a problem with my engine.

He does not hold idle and stalls.
I have placed the obd reader and it displays code p301, misfiring cylinder n ° 1
what I did:
invert the candles: identical problem
reverse the coils: identical problem
reversed injectors: identical problem
tested the injectors with a power supply: ok
changed the lambda probe after the catalyst
when I leave the coils connected to cylinder 1 the engine turns badly, when I unplug it sometimes it stalls,
sometimes it continues to turn badly (as if I was doing nothing)
any idea?
thx

 

[flash22]

Candles - I assume you meant spark plugs

Just to confirm you are testing the correct cylinder, No. 1 is on the left as you look at the engine

have you checked the power and ground to the No.1 coil also have you checked spark on coil No.1

Next step is to do a compression test

[Supertimor]

yes the spark plugs.
On the left side.

I checked the spark plug gap and it's ok.
To test the ignition I proceeded like this:
connected the coil to its power supply, put a spark plug and grounded. there was spark.

 

[flash22]

Is the coil getting its supply and signal from the ecu, same test but with the injector

 

[Antonio2]

Hi Dav.

Although the 0301 code indicates a No 1 cylinder mis-fire detection, it doesn't necessarily mean that the mis-fire problem is ignition related. 

It could also be caused by other factors such as a cylinder compression issue, fuel injector problem, valve clearance incorrect etc - so not necessarily a faulty spark plug or ignition coil. 

[Supertimor]

@flash: yes the spark is ok.

@ antonio: I used a screwdriver to listen if the injector makes a characteristic little click. And it makes a lot of noise. Normal noise, like the other 2. I also tested by reversing 2 injectors. Hope this is not a compression and problem valve issue ...

I manage to bring the engine to its maximum speed, but not sure that the 3 cylinders ignite the fuel

 

[Red_Corolla]

2 minutes ago, flash22 said:

Is the coil getting its supply and signal from the ecu, same test but with the injector

 

If the coil is firing the plug outside of the cylinder, I would say yes to the above.  I would think it's best to 100% confirm the ignition before turning to the injector, because the latter will normally be turned off after a few seconds without firing (to protect the cat). Feedback on the IGF circuit tells the ECU when the coils have fired, but a scope is needed to check that. Definitely worth doing a compression test at this point.

[flash22]

It could be any number of options - its a dead miss with no contribution - op has ruled out plug, coil and injector, just need to check the ecu is driving the coil and injector

Then a compression check - a burnt or bent valve

 

[Supertimor]

7 minutes ago, flash22 said:

It could be any number of options - its a dead miss with no contribution - op has ruled out plug, coil and injector, just need to check the ecu is driving the coil and injector

Then a compression check - a burnt or bent valve

 

any méthod to check the ecu is driving the coil and injector?

 

[Supertimor]

a detail that I forgot to mention but which is important: a few weeks ago the car had the same problem, with the engine and vsc warning light flashing. I reset with my obd tool, and unplugged the Battery and then it worked again ... this is why I am thinking of an electrical problem.

 

[Antonio2]

Bearing in mind you have an OBD tool, if it's a decent spec tool (not just a basic code reader), there maybe a menu within called "live data".

Using live data  allows you to see various values/measurements from various sensors when the engine is running. Assuming you have the 998cc IQ you could view the values pertinent to each of the 3 individual cylinder and compare them to each other. eg fuel injection duration etc. Obviously you would need access to the technical data, in order to see if the values shown (with varying engine running conditions) are correct, or out of spec ! If one of the cylinders showed values different to the other cylinder, (with the same running conditions), this could point you in the right direction.

You mentioned the fact that you had the engine and VSC warning light flashing. A failing Battery can SOMETIMES cause spurious warning lights to illuminate - even if the car may appear to start ok.

This can be because the drop in voltage from a "tired" Battery when starting the engine, may cause the Battery voltage to drop below a certain threshold, which a particular system may log as a fault condition - and then illuminate the system's warning lamp. Obviously your battery disconnection has reset the lamps. A local garage can use a dedicated battery tester to quickly establish the batteries "state of health" - not just it's terminal voltage (state of charge). I can see your IQ is a 2009 model. If your IQ is still using the original battery, it would definitely be worth getting it tested anyway.

As per messages above from other members, I would also suggest a compression test would be my first check.

[Supertimor]

thanks for your help.

for the compression, the tool is ordered I will receive it tomorrow.

The Battery is at 12.6v after 2 hours of rest, which does not seem so bad to me.

This is a Bosch S4023, is it the right model? It doesn't cost much, I'll buy a new one if it's the right one.
i found a yuaza YBX5057 better powered.

In the meantime I do a big charge with a charger that is going well.

 

For the OBD, I have some information but no analysis to compare the cylinders. and always a code p0301 ... cylinder 1 misfire.

[Supertimor]

compressions verified, I have 12bar at each cylinder.
the valve problem is ruled out (I prefer)

I also tried lifting the coil to listen if you hear the tactac of a spark and nothing ...
Surprising because the test I had done with an external candle gave me ignition ...

[flash22]

swap coil and plugs 1 and 3, clear the codes

[Supertimor]

4 hours ago, flash22 said:

swap coil and plugs 1 and 3, clear the codes

I do that before to call help here 😉
 

So the problem is solved, but i don't know

how it was resolved.

This afternoon, reception of the compressiometer.
Measurement, and 13 bars on each cylinder (good news)

Reassembly of the spark plugs by mixing the seats and the coils: present problem.

finally i decides to dismantle everything to take out the egr valve.
I test it, nothing in particular mechanically but nothing conclusive in electrical.

I check everything, I go back without conviction, and there the car turns nickel.

I did not do anything in particular compared to my previous checks

When I had my previous identical problem a few weeks ago it was after having drained the coolant,
and there having touched the liquid again and bleed, the car started again ...
it's strange because there is in theory no link ...
but hey I'll watch that.

 

Thanks for the helpers.