noblesenga

07 is250 175k km

Cylinder 4 misfire when i get to highway speeds 100kmph+. If i pull over, restart the car, the misfire goes away but comes back *** soon as i get up to highway speeds. No misfire on cold starts or during city driving.

• Replaced the cylinder 4 coil with cylinder 1 and the problem didn't follow
• Inspected the spark plug, no issue there as i replaced em 20k ago
• Replaced the spark plug with Cylinder 5 and same issue.

is the fuel injector going bad??

2013FSport

iTrader: (2)

Based on that; I would be looking at bad connections at the battery and / or alternator. The power steering and U1xxx codes are saying the whole CAN bus crashed which is pretty major.

Good start by swapping COPs. On the highway in higher gears presents higher engine loads hence the misfire. Did you move the plug too? If not, you should. They can fail and short.

You might clean the MAF sensor, disconnect battery, clean and check connections, and add some Techron fuel cleaner and see what happens with all those errors once reset.

noblesenga

i swapped coil 4 with 1. Same issue. Maybe i’ll try swapping the plugs aswell.

noblesenga

I swapped the spark plug and still same issue. P0304 misfiring on highway speeds AFTER the engine has been fully warmed up

Gville350

iTrader: (10)

Could this be the dreaded IS250 carbon build-up issue since the issue DOESN'T follow the coil packs nor the spark plug?

noblesenga

i doubt it since the problem only happen once the engine is warm and on the highway. I can rev it as hard as i want to during idle, no misfire.

2013FSport

iTrader: (2)

Do keep in mind that P030X code does not mean ignition 100% of the time.

It means the combustion cycle occurred (OR was supposed to) but it didn't accelerate the crankshaft efficiently... Meaning that cylinder did not contribute compared to the other 5 that did. The CPS knows this.

Meaning; options are many:
Compression, rings & valve sealing 4X
Air volume for combustion.
Plug and COP
Ignition Module (ECU)
Injection module (FCU)
Fuel Injector.

Careful examination of the removed spark plug should be a good indicator.

You need fuel trim data (LTFT & STFT). Engine load and coolant temperature.
I suggest you get Torque Pro or OBD Fusion to dig deeper.

noblesenga

There is no issue with plug and COP as i swapped em and nothing happened. Im thinking compression issue. I do have fuel trim available on blue driver. I also have techstream. I will post the data sometime this week.! thank for reply.

2013FSport

iTrader: (2)

Get the Freeze Frame Data too! See if always happens under the same conditions....

Nasa343

Did you resolve the issue?

noblesenga

yea i sold the car 🤣 but im sure it was injector issue

2013FSport

iTrader: (2)

And I went to all this mental anguish! ​

What did you replace it with?​​​​​​​​​​​​​​​​​​​​

MrHarris

iTrader: (1)

mannn how anti climatic lol. You sold the car with the issue still not resolved I assume? Did you just quietly omit the scenario specific issue to the new buyer?

tbear

Have the same issue with my new to me '10. Ordered plugs and a coil to try and fix. Hopefully that does it.

Are injectors hard to replace on these cars?

Nasa343

The injector are not very hard to replace, if you fix the issue please post your solution I’m still dealing with this