[Haggerty]

I've had years of injector issues and after the latest round I had them sonic cleaned at a business nearby. They all looked great and I threw them in. I still get smooth running errors and activation errors on mainly one injector. I found a thread where CBU cleaning got rid of someone's activation errors so I went ahead and bought all the walnut blasting gear and set it up. I go to take off my intake manifold and all my runners are wet, but largely clean of carbon. Previously they were filthy and well clogged, but now its just a thin layer on all walls, even the swirl flaps dont look bad. Even with my bore scope camera its hard to tell which valves are open, but they all look reasonably clean anyway. The car is stock. Im debating if I should even walnut blast at this point, but without doing something I guess my problems wont be fixing themselves...

[RL18]

Originally Posted by Haggerty

I've had years of injector issues and after the latest round I had them sonic cleaned at a business nearby. They all looked great and I threw them in. I still get smooth running errors and activation errors on mainly one injector. I found a thread where CBU cleaning got rid of someone's activation errors so I went ahead and bought all the walnut blasting gear and set it up. I go to take off my intake manifold and all my runners are wet, but largely clean of carbon. Previously they were filthy and well clogged, but now its just a thin layer on all walls, even the swirl flaps dont look bad. Even with my bore scope camera its hard to tell which valves are open, but they all look reasonably clean anyway. The car is stock. Im debating if I should even walnut blast at this point, but without doing something I guess my problems wont be fixing themselves...

What are you using for fuel?

When I deleted at 105k I never walnut blasted, just soaked the intake manifold then pressure washed it a few times.

[Haggerty]

I just use standard diesel from Irving. About every other tank I use Techron D cleaner if the car lasts that long just to keep the injector check engines at bay. I took the car apart last week to throw the cleaned injectors in and the CBU build up was pretty bad, which caused me to buy all the hardware. Now that I took it apart to start the walnut blast all the carbon is largely gone and I have no idea why. The biggest issue im having now is Cylinder 5 injector activation error which throws into limp mode before I can get a block, im going to try to swap it with another cylinder and see if it moves. I do have a new intake manifold from ebay for $130 coming, figured that was just easier than trying to clean it all and I'll have a second one on hand that I can just swap out when they need cleaned. Also have the swirl flap delete on the way.

[RL18]

Originally Posted by Haggerty

I just use standard diesel from Irving. About every other tank I use Techron D cleaner if the car lasts that long just to keep the injector check engines at bay. I took the car apart last week to throw the cleaned injectors in and the CBU build up was pretty bad, which caused me to buy all the hardware. Now that I took it apart to start the walnut blast all the carbon is largely gone and I have no idea why. The biggest issue im having now is Cylinder 5 injector activation error which throws into limp mode before I can get a block, im going to try to swap it with another cylinder and see if it moves. I do have a new intake manifold from ebay for $130 coming, figured that was just easier than trying to clean it all and I'll have a second one on hand that I can just swap out when they need cleaned. Also have the swirl flap delete on the way.

Okay. To me if cylinder 5 is throwing and injector activation error I'd just replace the injector. You can absolutely swap injectors to see if the problem persists but, I doubt that you're code is cbu related or swirl flap related. You would most likely see a airflow related code if that was the case.

With a sonic cleaning you may have cleaned the injectors but if there's an electrical issue that will still be there whether or not the nozzle is clean

[335dlci]

Meth cleans it.

[Haggerty]

Originally Posted by 335dlci

Meth cleans it.

yeah, that's part of long term goals. I deploy for a year and then get sent to Japan for 3 years. So I have 4 years to plan out my 335d build for when I move to a state that doesn't require emissions testing. Was hoping to get this thing running decent so I can give it to family for the time frame...or at least get it to sellable condition and just buy another in 4 years. Bad weather today, so the injector swap and recode will have to wait until tomorrow.

I've replaced 2 injectors with new ones and they quickly threw the same rough or activation codes last year and I've been limping along all this time on just resetting the check engine light while driving.

[BB_cuda]

You can have meth injection and still be legal.

[awenthol]

CBU in the intake is from blow-by mixing with EGR soot, and gluing. Less EGR or less sooty EGR (ie, fixing your injector issues) means less soot coming back into the intake.

Not going to get a "simple" answer, but a bunch of other factors will play into this--changes in driving behavior, idling, ambient weather (thermal cycling will break up hydrocarbons), and to some extent engine oil (better detergents, which will end up in the blow-by and therefore intake).

If people don't do CBU after deleting and do not run a catch-can, eventually the blow-by alone will clean everything.