2.0L Misfire code P0302 - Problem goes away when engine get warmed

[Turbo_Boss]

Hello Guys,

I really appreciated your help.

Cars is a 2009 BORA MK4 2.0L with only 51,500kms (The BORA MK4 is still in production in Mexico under the name Jetta Classic)

Just yesterday, when I started the engine in the morning it misfires stumble/hesitate and can fill a small shake in the engine, sometimes fill like a hiccup at idle. If the AC is on, the problem is a little more worst.

This was at my building garage, I was having my door open and I can fill a strong fuel odor (like when is very rich) I am pretty sure I have start the engine before in other occasions with my door open and never smell that strong fuel odor.

As soon as the engine get semi warm (engine not quite up to temp) the misfiring goes away and the car behave like nothing happened and runs perfectly. At Idle I still fill sometime the hiccup.

There is no illumination of the Check Engine Light..

Scan for codes with my OBD FUSION and it throw P0302 Cylinder 2 Misfire Detected

My car does not have/use a secondary air pump that goes on top of the four corners coil pack so I can easily see the coil pack.

So I went a make the test of using a spray water bottle to spray over the coil pack and there was no misfires neither any electrical arcing.

I done this test with the engine at idle and also with some body helping me pressing the gas accelerator to rise the RPM. I spray very heavily and there was not a single hiccup.

I then use a garden hose to throw a lot of water over the coil pack and neither misfired.

I have not removed yet the plugs to check them but these plugs are almost new. I installed new 101-000-033-AA OEM plugs at 41,500 Kms (Does was the same part number plugs I remove and the same part my VW dealer says my car use with my VIN No.)

Any advice what other test I can perform to pin point what is the exact part I need to change? Or what other test I can perform with the OBD Fusion code scanner? Maybe I can make a test when starting it in the morning before the engine get warmer.

I really don’t want to throw money changing and changing parts.

Thank you for your help and time.

Regards,

Isaac

[h100vw]

You haven't said what engine it is? Does it have coilepacks or an old school distributer. I know a lot of south American VWs soldiered on with older tech. An engine code would be a big help.

Anyway, spray water on coilpacks will likely not find anything as it's probably in the cylinder. I'd remove the sparkplugs for a look and also swap the #2 coilpack with another to see if the misfire moves with it.

The smooth running once up to temp could be related to the water temp sensor.

EDIT reading your post again it could be that it's what we know as a Bora. Which was discontinued in 2004 over here.

Give us more details please.

Hello Guys,

I really appreciated your help.

Cars is a 2009 Jetta MK4 2.0L with only 51,500kms (The Jetta MK4 is still in production in Mexico under the name Jetta Classic)

Just yesterday, when I started the engine in the morning it misfires stumble/hesitate and can fill a small shake in the engine, sometimes fill like a hiccup at idle. If the AC is on, the problem is a little more worst.

This was at my building garage, I was having my door open and I can fill a strong fuel odor (like when is very rich) I am pretty sure I have start the engine before in other occasions with my door open and never smell that strong fuel odor.

As soon as the engine get semi warm (engine not quite up to temp) the misfiring goes away and the car behave like nothing happened and runs perfectly. At Idle I still fill sometime the hiccup.

There is no illumination of the Check Engine Light..

Scan for codes with my OBD FUSION and it throw P0302 Cylinder 2 Misfire Detected

My car does not have/use a secondary air pump that goes on top of the four corners coil pack so I can easily see the coil pack.

So I went a make the test of using a spray water bottle to spray over the coil pack and there was no misfires neither any electrical arcing.

I done this test with the engine at idle and also with some body helping me pressing the gas accelerator to rise the RPM. I spray very heavily and there was not a single hiccup.

I then use a garden hose to throw a lot of water over the coil pack and neither misfired.

I have not removed yet the plugs to check them but these plugs are almost new. I installed new 101-000-033-AA OEM plugs at 41,500 Kms (Does was the same part number plugs I remove and the same part my VW dealer says my car use with my VIN No.)

Any advice what other test I can perform to pin point what is the exact part I need to change? Or what other test I can perform with the OBD Fusion code scanner? Maybe I can make a test when starting it in the morning before the engine get warmer.

I really don’t want to throw money changing and changing parts.

Thank you for your help and time.

Regards,

Isaac

[Turbo_Boss]

Hello,

Yes, in some countrys they called Bora

Engine is a 4 Cylinder 2.0L that use one coil pack were the four plugs wires goes conected (Is not Distribuitor) It also does not use coil over the plugs.

THX

Here is a pic of the coil pack it use. I found the pic on the net.

[h100vw]

Hello,

Yes, in some countrys they called Bora

Engine is a 4 Cylinder 2.0L that use one coil pack were the four plugs wires goes conected (Is not Distribuitor) It also does not use coil over the plugs.

THX

Here is a pic of the coil pack it use. I found the pic on the net.

Check the sparkplugs first, then maybe a water temp sensor. Also consider the 02 sensor as well.

VCDS is a better scan tool than what you have there.

Gavin

[grtuned]

Also don't rule out the coil leads for a misfire issue.

[RolfGolf]

The last time I had these issues, replacing the green coolant temperature sensor fixed them.

Wouldn't hurt to do a service including thermostat, spark plugs, air filter, oil filter and fuel filter anyway.