B757-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Aircraft; Manuals
After about 45 minutes in cruise [we] had very erratic and erroneous left engine indications. N3 erratic and surging; N2 erratic. Left bleed pressure fluctuated from 0 to 60 PSI; left engine bleed light on with loss of pressure and pack off light as well; left and center hydraulic pressure fluctuated from about 3090 to well over 3200 PSI. Right [was] also fluctuated. Status message; left engine speed card illuminated. Left engine center fuel pump pressure light [was] on with 3;000 LBS of fuel in tank. We were going to an airport where weather was not good so we diverted to nearest suitable airport.
Due to erratic indications of the left bleed air system; pressurization system; left fuel system; left engine indications and operation; and all hydraulic systems; a precautionary landing was made at the nearest suitable airport.
B757 flight crew experiences erratic engine indications in cruise with a Status Message; left engine speed card. With no QRH guidance available; the crew elects to divert to the nearest suitable airport.