I 've got no codes posted but an annoying negative LTFT from 9 to as high as 25, stays around neg 15. Os sensors are bopping around, one is a bit lazy. The STFT in the plus 5 to neg five range. Both banks. Map sensor has been cleaned as has the throttle. Yes on the PVC valve.
How long should it hold fuel pressure with the key off? I'm thinking I may have a leaking injector. Failed to mention fuel mileage sucks. Am trying some Lucas fuel treatment to clean it up. It has caused theLTFT to worsen.
Has anyone out their rebuilt their own injectors? go new or rebuilt? Enjoy the cool weather

 

How long does it hold pressure? If it bleeds off right away, that's bad..... You can simply unbolt the fuel rail from the intake, lift it up some, and cycle the pump a couple times to see if any of them are leaking. (DO NOT crank the engine like that..... )

How old are your O2 sensors?

 

Do the filter baskets of the injectors act as a valve seat for the injectors? If I have to pull the injectors to give them a looksee, I have to replace 25 year old o rings. If leaking, I was contemplating a shade tree injector overhaul. A kit is little more than the cost of o rings.
O2 sensors are OEM and have not been touched by me. I will check fuel pressure and leakage first.

 

Pull the injectors out of the intake, leave them in the rail. Rebuilding injectors is a waste of time, replace the o-rings, and call it a day.

If your O2s are original, may wanna consider replacing them... NTK or Denso sensors only please.

 

Considering the trouble to rebuild and the low price of new injectors, I'd just replace. I did a major tune up a few years ago and one thing I did was replace the injectors. The old ones were working but the new ones work better. Outside of a poorly cut home made TBI gasket, that has cold start issues, the truck purrs as good or better than a new truck.