Vortec 5.7l easy way to clean poppet valves?

[chris]

I have a 1998 Chevy C2500 with a 5.7l Vortec engine. I believe the poppet valves on the CSFI injector system are starting to get dirty because I get an intermittent engine light for a lean run on bank 2 (Checked Bnk2 spark plugs, they’re black) and an intermittent hard start. I’ve been priming the fuel pump 4 or 5 times when it won’t start and it seems to start fine after that.

I checked the fuel pressure through the valve before the injector spider and it’s good. I’ve replaced the bank 2 upstream o2 sensor, I’ve replaced the coolant temp sensor, I repaired vacuum leaks on the PCV hose, and checked for intake and vacuum leaks with carburetor cleaner, which there seems to be none. I cleaned the throttle body and MAF sensor, which seem to be functioning fine. The fuel trim on bank 2 fluctuates into the negatives periodically when idling; and while accelerating sits around 8-18%. Under hard acceleration I can hear what sounds like unburned fuel exploding inside of the bank 2 catalytic converter. The bank 2 cat also rattles sometimes as if the insides are starting to fall apart. I don’t need cats, and I don’t mind running without them. I have no exhaust leaks, two catalytic converters which connect to a single tailpipe and I have NO muffler.

After researching I believe the poppet valves on my fuel injectors are sticking up. I ran a couple treatments of Lucas fuel system cleaner through with slight improvement, but still the intermittent lean run code and fuel trim numbers I’m not happy with. I was wondering if anyone knows of a good way to clean the poppet valves without removing the plenum to take them out? I was thinking running water through the intake (Like Eric did to clean carbon build up in one of his videos) to steam-off all of the carbon buildup in the injector poppets. Any help would be appreciated, This was a $700 that has an amazing body, I’ve been dealing with this intermittent lean run and hard start since I’ve owned it and it’s frustrating. I don’t have the money right now to convert it to a MPFI spider and I’m looking for a temporary fix

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[chris]

Update: I’ve been running seafoam through my fuel constantly for a few weeks and it seems to be getting better slowly

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