114102 - Rough running, cylinder 1: Fuel-air mixture too rich.

[MOA90]

I have a 2020 Supra with 20,000 miles that started misfiring and running rough. Here are my mods, what I’ve tried to do to fix the issue and the codes it’s throwing. Any help on what could be causing this is greatly appreciated.

My fuel trims are in the -20’s for LTFT and range from -5 to +20 for STFT.


Mods:

• Remnant 65 Omega Turbo
• Port injection - 1000cc injectors
• Motiv Reflex with the TMS harness
• Intake
• Charge pipe
• Catless downpipe
• Full custom 3.5” exhaust
• Flex fuel sensor
• Flex fuel tune from Twisted Tuning on MHD

What I’ve tried:

• Replaced spark plugs with NGK and gapped to .030 right before this started happening
• Swapped spark plug from cylinder 1 to cylinder 3
• Swapped coil pack from cylinder 1 to cylinder 2
• Turned off port injection
• Tested direct injectors pressure after warming the car up and turning it off to make sure pressure climbs and it did
• New MAP sensor
• New 02 sensors
• Smoke leak test and didn’t find any leaks
• Compression test on cylinder 1

- DME active codes -

114102 - Rough running, cylinder 1: Fuel-air mixture too rich.
118002 - Mixture control: Fuel-air mixture too rich.
144055 - Rough running cylinder, mixture too rich: Multiple fault.

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[razorlab]

You made a thread like this before, no?

Have you done a boost leak check to see if you have any leaks at the intake manifold or injector o-rings?

Also, there is no MAF sensor, the sensor at the air filter is a temp sensor.

 

[Darkseid69]

Were the spark plugs oil fowled when you were removing them? Have u tried replacing the DI injectors on cyl 1 or 2?

 

[MOA90]

You made a thread like this before, no?

Have you done a boost leak check to see if you have any leaks at the intake manifold or injector o-rings?

Also, there is no MAF sensor, the sensor at the air filter is a temp sensor.

I did but it was all over the place so I wanted to condense it and put everything in one place. I also wasn't getting responses because of that.

I did a boost leak test and I don't have one, I also just talked to @boosted_jaz about this issue and he advised me of the temp sensor not being a MAF sensor lol. I have my spark plugs gapped to .030 and he said to get new plugs and gap them to .024 so I'm doing that today. This issue did occur pretty quickly after getting new plugs so who knows, maybe it's the plugs.

 

[MOA90]

Were the spark plugs oil fowled when you were removing them? Have u tried replacing the DI injectors on cyl 1 or 2?

They were pretty dark, which is why I replaced the plugs but going to replace them again because apparently they are at the incorrect gap (.030 instead of .024). I haven't replaced a direct injector though.

 

[itzTang]

You already swapped spark plugs and the misfire stays so doubt it’s the sparkies

 

[itzTang]

Try swapping the injectors

 

[MOA90]

I just replaced all the spark plugs and it’s still doing it. My cylinder 1 spark plug is darker than the rest of them. Would that indicate that it’s the injector?

 

[tracer bullet]

I just replaced all the spark plugs and it’s still doing it. My cylinder 1 spark plug is darker than the rest of them. Would that indicate that it’s the injector?

No guarantees, but yeah, it could. Running rich. Or burning oil. But you gave codes indicating it ran rich, so....

 

[MOA90]

No guarantees, but yeah, it could. Running rich. Or burning oil. But you gave codes indicating it ran rich, so....

Someone else told me bad injectors would turn the spark plugs white. Maybe it is oil.

 

[tracer bullet]

Someone else told me bad injectors would turn the spark plugs white.

That would be lean. Also an injector. Depends on the injector issue.

Don't disregard the injector possibility just because one of the ways it shows up isn't present. Many issues show up in different ways.

 

[MOA90]

That would be lean. Also an injector. Depends on the injector issue.

Don't disregard the injector possibility just because one of the ways it shows up isn't present. Many issues show up in different ways.

I don’t disagree, it could still be a leaky injector I guess.

 

[lucky phil]

I don’t disagree, it could still be a leaky injector I guess.

I'm surprised you haven't already replaced the injector as this has been going on for a while now. I thought you had in a previous thread but it got messy with others chiming in with the same issue I think. Anyway thats what I would do.

Phil

 

[MOA90]

I'm surprised you haven't already replaced the injector as this has been going on for a while now. I thought you had in a previous thread but it got messy with others chiming in with the same issue I think. Anyway thats what I would do.

Phil

I wasn't convinced it was an injector but it really seems to be the case so I’ll be doing it this weekend. This has been going on for a while but with snow and rain it’s been hard to drive the car for testing but with warmer weather I'm ready to get this fixed. Thanks for the help!

 

[razorlab]

I wasn't convinced it was an injector but it really seems to be the case so I’ll be doing it this weekend. This has been going on for a while but with snow and rain it’s been hard to drive the car for testing but with warmer weather I'm ready to get this fixed. Thanks for the help!

Just note the bolts for the rails are one-time use. You need to follow a very specific torque sequence as well.

Just replacing one injector means you have to take one half of the rail off, which houses three injectors. I would make sure you just take out the one injector and not the other two. If you take them out and need to reinstall them, you need to replace the lower seal and use the seal contraction tool. For new OEM injectors, no seal tool needed.

I just went through all of this installing S58 injectors.

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