97 Surburban, 198k, replaced heads with stock L31's recently due to a crack, did full tune up at the same time. All filters, fluids, spark plug, distributor, rotor, wires, etc. I'm getting +20%-25% (25% is the max for LTFT) about everywhere for both banks. I checked for vacuum leaks and didn't find anything. I think fuel pressure was fine as well, 60-65 PSI when cranking IIRC, could be mistaken on that number, but I remember it was within spec. New fuel pressure regulator, the fuel spider is still the old poppet style. O2 sensors oscilliate normally.
Any suggestions on what to look for? Fueling issue or unmetered air? I sprayed carb cleaner around the intake and etc and couldn't find any leaks. Both banks are within a few % in terms of fuel trim, so its something that's effecting all cylinders.
Any suggestions on what to look for? Fueling issue or unmetered air? I sprayed carb cleaner around the intake and etc and couldn't find any leaks. Both banks are within a few % in terms of fuel trim, so its something that's effecting all cylinders.