Are the stock TBI intake manifold bores feeding a common plenum chamber or does each bore feed four intake runners?
Question is raised as our 'burb is under performing these days (no pulling power on hills Canadian Rockies around 4000 Ft asl).
There is a natural power loss with altitude that pilots of normally aspirated piston engine aircraft know too well. This under performance can best be described as lack of accelerating power though the engine runs smoothly and has not set any codes.
The truck will bury the speedo needle on level roads without skipping or missing a beat. Just seems to take until next year to get there! Plugs, when last pulled were white with hard deposits at the base of the ground probe. Possible too lean I'm guessing . I'm not afraid to ask as I'm more familiar with turbine engines than piston engines. Timing? Injectors/pulse width? filters? fule pressure vs fuel flow? Thanks in advance Rolf